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	Author	Bal, K.M.; Neyts, E.C.
	Title	Extending and validating bubble nucleation rate predictions in a Lennard-Jones fluid with enhanced sampling methods and transition state theory			Type	A1 Journal article
	Year	2022	Publication	Journal Of Chemical Physics	Abbreviated Journal	J Chem Phys
	Volume	157	Issue	18	Pages	184113-10
	Keywords	A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	We calculate bubble nucleation rates in a Lennard-Jones fluid through explicit molecular dynamics simulations. Our approach-based on a recent free energy method (dubbed reweighted Jarzynski sampling), transition state theory, and a simple recrossing correction-allows us to probe a fairly wide range of rates in several superheated and cavitation regimes in a consistent manner. Rate predictions from this approach bridge disparate independent literature studies on the same model system. As such, we find that rate predictions based on classical nucleation theory, direct brute force molecular dynamics simulations, and seeding are consistent with our approach and one another. Published rates derived from forward flux sampling simulations are, however, found to be outliers. This study serves two purposes: First, we validate the reliability of common modeling techniques and extrapolation approaches on a paradigmatic problem in materials science and chemical physics. Second, we further test our highly generic recipe for rate calculations, and establish its applicability to nucleation processes.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000885260600002	Publication Date	2022-11-14
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0021-9606	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	4.4	Times cited		Open Access	OpenAccess
	Notes				Approved	Most recent IF: 4.4
	Call Number	UA @ admin @ c:irua:192076			Serial	7266
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	Author	Bal, K.M.
	Title	Reweighted Jarzynski sampling : acceleration of rare events and free energy calculation with a bias potential learned from nonequilibrium work			Type	A1 Journal article
	Year	2021	Publication	Journal Of Chemical Theory And Computation	Abbreviated Journal	J Chem Theory Comput
	Volume	17	Issue	11	Pages	6766-6774
	Keywords	A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	We introduce a simple enhanced sampling approach for the calculation of free energy differences and barriers along a one-dimensional reaction coordinate. First, a small number of short nonequilibrium simulations are carried out along the reaction coordinate, and the Jarzynski equality is used to learn an approximate free energy surface from the nonequilibrium work distribution. This free energy estimate is represented in a compact form as an artificial neural network and used as an external bias potential to accelerate rare events in a subsequent molecular dynamics simulation. The final free energy estimate is then obtained by reweighting the equilibrium probability distribution of the reaction coordinate sampled under the influence of the external bias. We apply our reweighted Jarzynski sampling recipe to four processes of varying scales and complexities.spanning chemical reaction in the gas phase, pair association in solution, and droplet nucleation in supersaturated vapor. In all cases, we find reweighted Jarzynski sampling to be a very efficient strategy, resulting in rapid convergence of the free energy to high precision.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000718183600008	Publication Date	2021-10-29
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1549-9618	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	5.245	Times cited		Open Access	OpenAccess
	Notes				Approved	Most recent IF: 5.245
	Call Number	UA @ admin @ c:irua:184676			Serial	8479
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	Author	Bal, K.M.; Neyts, E.C.
	Title	Quantifying the impact of vibrational nonequilibrium in plasma catalysis: insights from a molecular dynamics model of dissociative chemisorption			Type	A1 Journal Article;plasma catalysis
	Year	2021	Publication	Journal Of Physics D-Applied Physics	Abbreviated Journal	J Phys D Appl Phys
	Volume	54	Issue	39	Pages	394004
	Keywords	A1 Journal Article;plasma catalysis; vibrational nonequilibrium; dissociative chemisorption; free energy barriers; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ;
	Abstract	The rate, selectivity and efficiency of plasma-based conversion processes is strongly affected by nonequilibrium phenomena. High concentrations of vibrationally excited molecules are such a plasma-induced effect. It is frequently assumed that vibrationally excited molecules are important in plasma catalysis because their presence lowers the apparent activation energy of dissociative chemisorption reactions and thus increases the conversion rate. A detailed atomic-level understanding of vibrationally stimulated catalytic reactions in the context of plasma catalysis is however lacking. Here, we couple a recently developed statistical model of a plasma-induced vibrational nonequilibrium to molecular dynamics simulations, enhanced sampling methods, and machine learning techniques. We quantify the impact of a vibrational nonequilibrium on the dissociative chemisorption barrier of H2 and CH4 on nickel catalysts over a wide range of vibrational temperatures. We investigate the effect of surface structure and compare the role of different vibrational modes of methane in the dissociation process. For low vibrational temperatures, very high vibrational efficacies are found, and energy in bend vibrations appears to dominate the dissociation of methane. The relative impact of vibrational nonequilibrium is much higher on terrace sites than on surface steps. We then show how our simulations can help to interpret recent experimental results, and suggest new paths to a better understanding of plasma catalysis.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000674464100001	Publication Date	2021-09-30
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0022-3727	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.588	Times cited		Open Access	OpenAccess
	Notes	Fonds Wetenschappelijk Onderzoek, 12ZI420N ; K M B was funded as a junior postdoctoral fellow of the FWO (Research Foundation—Flanders), Grant 12ZI420N. The computational resources and services used in this work were provided by the HPC core facility CalcUA of the Universiteit Antwerpen, and VSC (Flemish Supercomputer Center), funded by the FWO and the Flemish Government. HLDA calculations were performed with a script provided by G Piccini.			Approved	Most recent IF: 2.588
	Call Number	PLASMANT @ plasmant @c:irua:179830			Serial	6808
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	Author	Bal, K.M.
	Title	Nucleation rates from small scale atomistic simulations and transition state theory			Type	A1 Journal article
	Year	2021	Publication	Journal Of Chemical Physics	Abbreviated Journal	J Chem Phys
	Volume	155	Issue	14	Pages	144111
	Keywords	A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	The evaluation of nucleation rates from molecular dynamics trajectories is hampered by the slow nucleation time scale and impact of finite size effects. Here, we show that accurate nucleation rates can be obtained in a very general fashion relying only on the free energy barrier, transition state theory, and a simple dynamical correction for diffusive recrossing. In this setup, the time scale problem is overcome by using enhanced sampling methods, in casu metadynamics, whereas the impact of finite size effects can be naturally circumvented by reconstructing the free energy surface from an appropriate ensemble. Approximations from classical nucleation theory are avoided. We demonstrate the accuracy of the approach by calculating macroscopic rates of droplet nucleation from argon vapor, spanning 16 orders of magnitude and in excellent agreement with literature results, all from simulations of very small (512 atom) systems.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000755502100008	Publication Date	2021-09-30
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0021-9606	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.965	Times cited		Open Access	OpenAccess
	Notes				Approved	Most recent IF: 2.965
	Call Number	UA @ admin @ c:irua:184937			Serial	8320
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	Author	Marinov, D.; de Marneffe, J.-F.; Smets, Q.; Arutchelvan, G.; Bal, K.M.; Voronina, E.; Rakhimova, T.; Mankelevich, Y.; El Kazzi, S.; Nalin Mehta, A.; Wyndaele, P.-J.; Heyne, M.H.; Zhang, J.; With, P.C.; Banerjee, S.; Neyts, E.C.; Asselberghs, I.; Lin, D.; De Gendt, S.
	Title	Reactive plasma cleaning and restoration of transition metal dichalcogenide monolayers			Type	A1 Journal article
	Year	2021	Publication	npj 2D Materials and Applications	Abbreviated Journal	npj 2D Mater Appl
	Volume	5	Issue	1	Pages	17
	Keywords	A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	The cleaning of two-dimensional (2D) materials is an essential step in the fabrication of future devices, leveraging their unique physical, optical, and chemical properties. Part of these emerging 2D materials are transition metal dichalcogenides (TMDs). So far there is limited understanding of the cleaning of “monolayer” TMD materials. In this study, we report on the use of downstream H<sub>2</sub>plasma to clean the surface of monolayer WS<sub>2</sub>grown by MOCVD. We demonstrate that high-temperature processing is essential, allowing to maximize the removal rate of polymers and to mitigate damage caused to the WS<sub>2</sub>in the form of sulfur vacancies. We show that low temperature in situ carbonyl sulfide (OCS) soak is an efficient way to resulfurize the material, besides high-temperature H<sub>2</sub>S annealing. The cleaning processes and mechanisms elucidated in this work are tested on back-gated field-effect transistors, confirming that transport properties of WS<sub>2</sub>devices can be maintained by the combination of H<sub>2</sub>plasma cleaning and OCS restoration. The low-damage plasma cleaning based on H<sub>2</sub>and OCS is very reproducible, fast (completed in a few minutes) and uses a 300 mm industrial plasma etch system qualified for standard semiconductor pilot production. This process is, therefore, expected to enable the industrial scale-up of 2D-based devices, co-integrated with silicon technology.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000613258900001	Publication Date	2021-01-28
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2397-7132	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor		Times cited		Open Access	OpenAccess
	Notes	Daniil Marinov has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No 752164. Ekaterina Voronina, Yuri Mankelevitch, and Tatyana Rakhimova are thankful to the Russian Science Foundation (RSF) for financial support (Grant No. 16-12-10361). This study was carried out using the equipment of the shared research facilities of high-performance computing resources at Lomonosov Moscow State University and the computational resources and services of the HPC core facility CalcUA of the University of Antwerp, and VSC (Flemish Supercomputer Center), funded by the Research Foundation-Flanders (FWO) and the Flemish Government. Patrick With gratefully acknowledges imec’s CTO office for financial support during his stay at imec. The authors thank Mr. Surajit Sutar (imec) for his help during sample electrical characterization, and Patrick Verdonck for lab processing. Jean-François de Marneffe thank Prof. Simone Napolitano from the Free University of Brussels for useful discussions on irreversibly adsorbed polymer layers, and Cédric Huyghebaert (imec) for his continuous support in the framework of the Graphene FET Flagship core project. All authors acknowledge the support of imec’s pilot line and materials characterization and analysis (MCA) group, namely Jonathan Ludwig, Stefanie Sergeant, Thomas Nuytten, Olivier Richard, and Thierry Conard. Finally, Daniil Marinov thank Mikhail Krishtab (imec/KU Leuven) for his help in selecting the optimal plasma etch system for this work. Part of this project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 649953.			Approved	Most recent IF: NA
	Call Number	PLASMANT @ plasmant @c:irua:175871			Serial	6671
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	Author	Izadi, M.E.; Bal, K.M.; Maghari, A.; Neyts, E.C.
	Title	Reaction mechanisms of C(³P_J) and C⁺(²P_J) with benzene in the interstellar medium from quantum mechanical molecular dynamics simulations			Type	A1 Journal article
	Year	2021	Publication	Physical Chemistry Chemical Physics	Abbreviated Journal	Phys Chem Chem Phys
	Volume	23	Issue	7	Pages	4205-4216
	Keywords	A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	While spectroscopic data on small hydrocarbons in interstellar media in combination with crossed molecular beam (CMB) experiments have provided a wealth of information on astrochemically relevant species, much of the underlying mechanistic pathways of their formation remain elusive. Therefore, in this work, the chemical reaction mechanisms of C(<sup>3</sup>P<sub>J</sub>) + C<sub>6</sub>H<sub>6</sub>and C<sup>+</sup>(<sup>2</sup>P) + C<sub>6</sub>H<sub>6</sub>systems using the quantum mechanical molecular dynamics (QMMD) technique at the PBE0-D3(BJ) level of theory is investigated, mimicking a CMB experiment. Both the dynamics of the reactions as well as the electronic structure for the purpose of the reaction network are evaluated. The method is validated for the first reaction by comparison to the available experimental data. The reaction scheme for the C(<sup>3</sup>P<sub>J</sub>) + C<sub>6</sub>H<sub>6</sub>system covers the literature data,<italic>e.g.</italic>the major products are the 1,2-didehydrocycloheptatrienyl radical (C<sub>7</sub>H<sub>5</sub>) and benzocyclopropenyl radical (C<sub>6</sub>H<sub>5</sub>–CH), and it reveals the existence of less common pathways for the first time. The chemistry of the C<sup>+</sup>(<sup>2</sup>P<sub>J</sub>) + C<sub>6</sub>H<sub>6</sub>system is found to be much richer, and we have found that this is because of more exothermic reactions in this system in comparison to those in the C(<sup>3</sup>P<sub>J</sub>) + C<sub>6</sub>H<sub>6</sub>system. Moreover, using the QMMD simulation, a number of reaction paths have been revealed that produce three distinct classes of reaction products with different ring sizes. All in all, at all the collision energies and orientations, the major product is the heptagon molecular ion for the ionic system. It is also revealed that the collision orientation has a dominant effect on the reaction products in both systems, while the collision energy mostly affects the charged system. These simulations both prove the applicability of this approach to simulate crossed molecular beams, and provide fundamental information on reactions relevant for the interstellar medium.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000621595300016	Publication Date	2021-01-18
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1463-9076	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	4.123	Times cited		Open Access	OpenAccess
	Notes	Fonds Wetenschappelijk Onderzoek, 12ZI420N ; Ministry of Science Research and Technology; Universiteit Antwerpen; The financial support from the Iran Ministry of Science, Research and Technology and PLASMANT Research Group University of Antwerp is highly acknowledged by the authors. K.M.B. was funded as a junior postdoctoral fellow of the FWO (Research Foundation – Flanders), Grant 12ZI420N. The computational resources and services used in this work were provided by the HPC core facility CalcUA of the Universiteit Antwerpen, and VSC (Flemish Supercomputer Center), funded by the FWO and the Flemish Government.			Approved	Most recent IF: 4.123
	Call Number	PLASMANT @ plasmant @c:irua:176672			Serial	6742
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	Author	Fukuhara, S.; Bal, K.M.; Neyts, E.C.; Shibuta, Y.
	Title	Entropic and enthalpic factors determining the thermodynamics and kinetics of carbon segregation from transition metal nanoparticles			Type	A1 Journal article
	Year	2021	Publication	Carbon	Abbreviated Journal	Carbon
	Volume	171	Issue		Pages	806-813
	Keywords	A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	The free energy surface (FES) for carbon segregation from nickel nanoparticles is obtained from advanced molecular dynamics simulations. A suitable reaction coordinate is developed that can distinguish dissolved carbon atoms from segregated dimers, chains and junctions on the nanoparticle surface. Because of the typically long segregation time scale (up to ms), metadynamics simulations along the developed reaction coordinate are used to construct FES over a wide range of temperatures and carbon concentrations. The FES revealed the relative stability of different stages in the segregation process, and free energy barriers and rates of the individual steps could then be calculated and decomposed into enthalpic and entropic contributions. As the carbon concentration in the nickel nanoparticle increases, segregated carbon becomes more stable in terms of both enthalpy and entropy. The activation free energy of the reaction also decreases with the increase of carbon concentration, which can be mainly attributed to entropic effects. These insights and the methodology developed to obtain them improve our understanding of carbon segregation process across materials science in general, and the nucleation and growth of carbon nanotube in particular.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000598371500084	Publication Date	2020-09-25
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0008-6223	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	6.337	Times cited		Open Access	OpenAccess
	Notes	Scientific Research, 19H02415 ; JSPS, 18J22727 ; Japan Society for the Promotion of Science; JSPS; JSPS; FWO; Research Foundation; Flanders, 12ZI420N ; This work was supported by Grant-in-Aid for Scientiﬁc Research (B) (No.19H02415) and Grant-in-Aid for JSPS Research Fellow (No.18J22727) from Japan Society for the Promotion of Science (JSPS), Japan. S.F. was supported by JSPS through the Program for 812			Approved	Most recent IF: 6.337
	Call Number	PLASMANT @ plasmant @c:irua:172452			Serial	6421
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	Author	Bal, K.M.; Fukuhara, S.; Shibuta, Y.; Neyts, E.C.
	Title	Free energy barriers from biased molecular dynamics simulations			Type	A1 Journal article
	Year	2020	Publication	Journal Of Chemical Physics	Abbreviated Journal	J Chem Phys
	Volume	153	Issue	11	Pages	114118
	Keywords	A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	Atomistic simulation methods for the quantification of free energies are in wide use. These methods operate by sampling the probability density of a system along a small set of suitable collective variables (CVs), which is, in turn, expressed in the form of a free energy surface (FES). This definition of the FES can capture the relative stability of metastable states but not that of the transition state because the barrier height is not invariant to the choice of CVs. Free energy barriers therefore cannot be consistently computed from the FES. Here, we present a simple approach to calculate the gauge correction necessary to eliminate this inconsistency. Using our procedure, the standard FES as well as its gauge-corrected counterpart can be obtained by reweighing the same simulated trajectory at little additional cost. We apply the method to a number of systems—a particle solvated in a Lennard-Jones fluid, a Diels–Alder reaction, and crystallization of liquid sodium—to demonstrate its ability to produce consistent free energy barriers that correctly capture the kinetics of chemical or physical transformations, and discuss the additional demands it puts on the chosen CVs. Because the FES can be converged at relatively short (sub-ns) time scales, a free energy-based description of reaction kinetics is a particularly attractive option to study chemical processes at more expensive quantum mechanical levels of theory.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000574665600004	Publication Date	2020-09-21
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0021-9606	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	4.4	Times cited		Open Access
	Notes	Japan Society for the Promotion of Science, 19H02415 18J22727 ; Fonds Wetenschappelijk Onderzoek, 12ZI420N ; This work was supported, in part, by a Grant-in-Aid for Scientific Research (B) (Grant No. 19H02415) and Grant-in-Aid for a JSPS Research Fellow (Grant No. 18J22727) from the Japan Society for the Promotion of Science (JSPS), Japan. K.M.B. was funded as a junior postdoctoral fellow of the FWO (Research Foundation – Flanders), Grant No. 12ZI420N. S.F. was supported by JSPS through the Program for Leading Graduate Schools (MERIT). The computational resources and services used in this work were provided by the HPC core facility CalcUA of the Universiteit Antwerpen, and VSC (Flemish Supercomputer Center), funded by the FWO and the Flemish Government. The authors are grateful to Pablo Piaggi for making the pair entropy CV code publicly available.			Approved	Most recent IF: 4.4; 2020 IF: 2.965
	Call Number	PLASMANT @ plasmant @c:irua:172456			Serial	6420
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	Author	Jafarzadeh, A.; Bal, K.M.; Bogaerts, A.; Neyts, E.C.
	Title	Activation of CO₂on Copper Surfaces: The Synergy between Electric Field, Surface Morphology, and Excess Electrons			Type	A1 Journal article
	Year	2020	Publication	Journal Of Physical Chemistry C	Abbreviated Journal	J Phys Chem C
	Volume	124	Issue	12	Pages	6747-6755
	Keywords	A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	In this work, we use density functional theory calculations to study the combined eﬀect of external electric ﬁelds, surface morphology, and surface charge on CO2 activation over Cu(111), Cu(211), Cu(110), and Cu(001) surfaces. We observe that the binding energy of the CO2 molecule on Cu surfaces increases signiﬁcantly upon increasing the applied electric ﬁeld strength. In addition, rougher surfaces respond more eﬀectively to the presence of the external electric ﬁeld toward facilitating the formation of a carbonate-like CO2 structure and the transformation of the most stable adsorption mode from physisorption to chemisorption. The presence of surface charges further strengthens the electric ﬁeld eﬀect and consequently causes an improved bending of the CO2 molecule and C−O bond length elongation. On the other hand, a net charge in the absence of an externally applied electric ﬁeld shows only a marginal eﬀect on CO2 binding. The chemisorbed CO2 is more stable and further activated when the eﬀects of an external electric ﬁeld, rough surface, and surface charge are combined. These results can help to elucidate the underlying factors that control CO2 activation in heterogeneous and plasma catalysis, as well as in electrochemical processes.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000526396900030	Publication Date	2020-03-26
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1932-7447	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.7	Times cited		Open Access
	Notes	Bijzonder Onderzoeksfonds, 32249 ; The ﬁnancial support from the TOP research project of the Research Fund of the University of Antwerp (grant ID: 32249) is highly acknowledged by the authors. The computational resources used in this study were provided by the VSC (Flemish Supercomputer Center), funded by the FWO and the Flemish Governmentdepartment EWI.			Approved	Most recent IF: 3.7; 2020 IF: 4.536
	Call Number	PLASMANT @ plasmant @c:irua:168606			Serial	6361
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	Author	Fukuhara, S.; Bal, K.M.; Neyts, E.C.; Shibuta, Y.
	Title	Accelerated molecular dynamics simulation of large systems with parallel collective variable-driven hyperdynamics			Type	A1 Journal article
	Year	2020	Publication	Computational Materials Science	Abbreviated Journal	Comp Mater Sci
	Volume	177	Issue		Pages	109581
	Keywords	A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	The limitation in time and length scale is a major issue of molecular dynamics (MD) simulation. Although several methods have been developed to extend the MD time scale, their performance usually deteriorates with increasing system size. Therefore, an acceleration method which is applicable to large systems is required to bridge the gap between the MD simulations and target phenomena. In this study, an accelerated MD method for large system is developed based on the collective variable-driven hyperdynamics (CVHD) method [K.M. Bal and E.C. Neyts, 2015]. The key idea is to run CVHD in parallel with rate control and accelerate multiple possible events simultaneously. Using this novel method, carbon diﬀusion in bcc-iron bicrystal with grain boundary is examined as an application for practical materials. Carbon atoms reaching at the grain boundary are trapped whereas carbon atoms in the bulk region diﬀuse randomly, and both dynamic regimes can be simultaneously accelerated with the parallel CVHD technique.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000519576300001	Publication Date	2020-02-08
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0927-0256	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.3	Times cited		Open Access
	Notes	JSPS, J22727 ; Japan Society for the Promotion of Science; This work was supported by Grant-in-Aid for Scientiﬁc Research (B) (No.19H02415) and Grant-in-Aid for JSPS Research Fellow (No.18J22727) from Japan Society for the Promotion of Science (JSPS), Japan. S.F. was supported by JSPS through the Program for Leading Graduate Schools (MERIT). Data availability The data required to reproduce these ﬁndings are available from the corresponding authors upon reasonable request.			Approved	Most recent IF: 3.3; 2020 IF: 2.292
	Call Number	PLASMANT @ plasmant @c:irua:166773			Serial	6333
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	Author	Bal, K.M.; Bogaerts, A.; Neyts, E.C.
	Title	Ensemble-Based Molecular Simulation of Chemical Reactions under Vibrational Nonequilibrium			Type	A1 Journal article
	Year	2020	Publication	Journal Of Physical Chemistry Letters	Abbreviated Journal	J Phys Chem Lett
	Volume	11	Issue	2	Pages	401-406
	Keywords	A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	We present an approach to incorporate the eﬀect of vibrational nonequilibrium in molecular dynamics (MD) simulations. A perturbed canonical ensemble, in which selected modes are excited to higher temperature while all others remain equilibrated at low temperature, is simulated by applying a speciﬁcally tailored bias potential. Our method can be readily applied to any (classical or quantum mechanical) MD setup at virtually no additional computational cost and allows the study of reactions of vibrationally excited molecules in nonequilibrium environments such as plasmas. In combination with enhanced sampling methods, the vibrational eﬃcacy and mode selectivity of vibrationally stimulated reactions can then be quantiﬁed in terms of chemically relevant observables, such as reaction rates and apparent free energy barriers. We ﬁrst validate our method for the prototypical hydrogen exchange reaction and then show how it can capture the eﬀect of vibrational excitation on a symmetric SN2 reaction and radical addition on CO2.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000508473400008	Publication Date	2020-01-16
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1948-7185	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	5.7	Times cited		Open Access
	Notes	Universiteit Antwerpen; Fonds Wetenschappelijk Onderzoek, 12ZI420N ; Departement Economie, Wetenschap en Innovatie van de Vlaamse Overheid; K.M.B. was funded as a junior postdoctoral fellow of the FWO (Research Foundation − Flanders), Grant 12ZI420N, and through a TOP-BOF research project of the University of Antwerp. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the FWO and the Flemish Government− department EWI.			Approved	Most recent IF: 5.7; 2020 IF: 9.353
	Call Number	PLASMANT @ plasmant @c:irua:165587			Serial	5442
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	Author	Bal, K.M.; Neyts, E.C.
	Title	Overcoming Old Scaling Relations and Establishing New Correlations in Catalytic Surface Chemistry: Combined Effect of Charging and Doping			Type	A1 Journal article
	Year	2019	Publication	The journal of physical chemistry: C : nanomaterials and interfaces	Abbreviated Journal	J Phys Chem C
	Volume	123	Issue	10	Pages	6141-6147
	Keywords	A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	Optimization of catalytic materials for a given application is greatly constrained by linear scaling relations. Recently, however, it has been demonstrated that it is possible to reversibly modulate the chemisorption of molecules on nanomaterials by charging (i.e., injection or removal of electrons) and hence reversibly and selectively modify catalytic activity beyond structure−activity correlations. The fundamental physical relation between the properties of the material, the charging process, and the chemisorption energy, however, remains unclear, and a systematic exploration and optimization of charge-switchable sorbent materials is not yet possible. Using hybrid DFT calculations of CO2 chemisorption on hexagonal boron nitride nanosheets with several types of defects and dopants, we here reveal the existence of fundamental correlations between the electron aﬃnity of a material and charge-induced chemisorption, show how defect engineering can be used to modulate the strength and eﬃciency of the adsorption process, and demonstrate that excess electrons stabilize many topological defects. We then show how these insights could be exploited in the development of new electrocatalytic materials and the synthesis of doped nanomaterials. Moreover, we demonstrate that calculated chemical properties of charged materials are highly sensitive to the employed computational methodology because of the self-interaction error, which underlines the theoretical challenge posed by such systems.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000461537400035	Publication Date	2019-03-14
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1932-7447	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	4.536	Times cited	5	Open Access	Not_Open_Access: Available from 21.02.2020
	Notes	Fonds Wetenschappelijk Onderzoek, 11V8915N ;			Approved	Most recent IF: 4.536
	Call Number	PLASMANT @ plasmant @UA @ admin @ c:irua:158117			Serial	5160
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	Author	Jafarzadeh, A.; Bal, K.M.; Bogaerts, A.; Neyts, E.C.
	Title	CO₂ activation on TiO₂-supported Cu₅ and Ni₅ nanoclusters : effect of plasma-induced surface charging			Type	A1 Journal article
	Year	2019	Publication	The journal of physical chemistry: C : nanomaterials and interfaces	Abbreviated Journal	J Phys Chem C
	Volume	123	Issue	11	Pages	6516-6525
	Keywords	A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	Surface charging is an often overlooked factor in many plasma-surface interactions and in particular in plasma catalysis. In this study, we investigate the effect of excess electrons induced by a plasma on the adsorption properties of CO2 on titania-supported Cu-5 and Ni-5 clusters using spin-polarized and dispersion-corrected density functional theory calculations. The effect of excess electrons on the adsorption of Ni and Cu pentamers as well as on CO2 adsorption on a pristine anatase TiO2(101) slab is studied. Our results indicate that adding plasma-induced excess electrons to the system leads to further stabilization of the bent CO2 structure. Also, dissociation of CO2 on charged clusters is energetically more favorable than on neutral clusters. We hypothesize that surface charge is a plausible cause for the synergistic effects sometimes observed in plasma catalysis.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000462260700024	Publication Date	2019-02-21
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1932-7447; 1932-7455	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	4.536	Times cited	4	Open Access	OpenAccess
	Notes				Approved	Most recent IF: 4.536
	Call Number	UA @ admin @ c:irua:159422			Serial	5281
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	Author	Aussems, D.U.B.; Bal, K.M.; Morgan, T.W.; van de Sanden, M.C.M.; Neyts, E.C.
	Title	Mechanisms of elementary hydrogen ion-surface interactions during multilayer graphene etching at high surface temperature as a function of flux			Type	A1 Journal article
	Year	2018	Publication	Carbon	Abbreviated Journal	Carbon
	Volume	137	Issue		Pages	527-532
	Keywords	A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	In order to optimize the plasma-synthesis and modification process of carbon nanomaterials for applications such as nanoelectronics and energy storage, a deeper understanding of fundamental hydrogengraphite/graphene interactions is required. Atomistic simulations by Molecular Dynamics have proven to be indispensable to illuminate these phenomena. However, severe time-scale limitations restrict them to very fast processes such as reflection, while slow thermal processes such as surface diffusion and molecular desorption are commonly inaccessible. In this work, we could however reach these thermal processes for the first time at time-scales and surface temperatures (1000 K) similar to high-flux plasma exposure experiments during the simulation of multilayer graphene etching by 5 eV H ions. This was achieved by applying the Collective Variable-Driven Hyperdynamics biasing technique, which extended the inter-impact time over a range of six orders of magnitude, down to a more realistic ion-flux of 1023m2s1. The results show that this not only causes a strong shift from predominant ion-to thermally induced interactions, but also significantly affects the hydrogen uptake and surface evolution. This study thus elucidates H ion-graphite/graphene interaction mechanisms and stresses the importance of including long time-scales in atomistic simulations at high surface temperatures to understand the dynamics of the ion-surface system.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000440661700056	Publication Date	2018-05-24
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0008-6223	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	6.337	Times cited	4	Open Access	Not_Open_Access: Available from 25.05.2020
	Notes	DIFFER is part of the Netherlands Organisation for Scientific Research (NWO). K.M.B. is funded as PhD fellow (aspirant) of the FWO-Flanders (Fund for Scientific Research-Flanders), Grant 11V8915N. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the FWO and the Flemish Government e department EWI.			Approved	Most recent IF: 6.337
	Call Number	PLASMANT @ plasmant @c:irua:152172			Serial	4993
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	Author	Huygh, S.; Bogaerts, A.; Bal, K.M.; Neyts, E.C.
	Title	High Coke Resistance of a TiO₂Anatase (001) Catalyst Surface during Dry Reforming of Methane			Type	A1 Journal Article
	Year	2018	Publication	Journal Of Physical Chemistry C	Abbreviated Journal	J Phys Chem C
	Volume	122	Issue	17	Pages	9389-9396
	Keywords	A1 Journal Article; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ;
	Abstract	The resistance of a TiO2 anatase (001) surface to coke formation was studied in the context of dry reforming of methane using density functional theory (DFT) calculations. As carbon atoms act as precursors for coke formation, the resistance to coke formation can be measured by the carbon coverage of the surface. This is related to the stability of different CHx (x = 0−3) species and their rate of hydrogenation and dehydrogenation on the TiO2 surface. Therefore, we studied the reaction mechanisms and their corresponding rates as a function of the temperature for the dehydrogenation of the species on the surface. We found that the stabilities of C and CH are significantly lower than those of CH3 and CH2. The hydrogenation rates of the different species are significantly higher than the dehydrogenation rates in a temperature range of 300−1000 K. Furthermore, we found that dehydrogenation of CH3, CH2, and CH will only occur at appreciable rates starting from 600, 900, and 900 K, respectively. On the basis of these results, it is clear that the anatase (001) surface has a high coke resistance, and it is thus not likely that the surface will become poisoned by coke during dry reforming of methane. As the rate limiting step in dry reforming is the dissociative adsorption of CH4, we studied an alternative approach to thermal catalysis. We found that the temperature threshold for dry reforming is at least 700 K. This threshold temperature may be lowered by the use of plasma-catalysis, where the appreciable rates of adsorption of plasma-generated CHx radicals result in bypassing the rate limiting step of the reaction.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000431723700014	Publication Date	2018-05-03
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1932-7447	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	4.536	Times cited	1	Open Access	OpenAccess
	Notes	Federaal Wetenschapsbeleid, IAP/7 ; Fonds Wetenschappelijk Onderzoek, G.0217.14N ; Onderzoeksfonds, Universiteit Antwerpen, 32249 ;			Approved	Most recent IF: 4.536
	Call Number	PLASMANT @ plasmant @c:irua:151529c:irua:152816			Serial	5000
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	Author	Bal, K.M.; Neyts, E.C.
	Title	Modelling molecular adsorption on charged or polarized surfaces: a critical flaw in common approaches			Type	A1 Journal article
	Year	2018	Publication	Physical chemistry, chemical physics	Abbreviated Journal	Phys Chem Chem Phys
	Volume	20	Issue	13	Pages	8456-8459
	Keywords	A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	A number of recent computational material design studies based on density functional theory (DFT) calculations have put forward a new class of materials with electrically switchable chemical characteristics that can be exploited in the development of tunable gas storage and electrocatalytic applications. We find systematic flaws in almost every computational study of gas adsorption on polarized or charged surfaces, stemming from an improper and unreproducible treatment of periodicity, leading to very large errors of up to 3 eV in some cases. Two simple corrective procedures that lead to consistent results are proposed, constituting a crucial course correction to the research in the field.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000428779700007	Publication Date	2018-03-12
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1463-9076	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	4.123	Times cited	8	Open Access	OpenAccess
	Notes	K. M. B. is funded as PhD fellow (aspirant) of the FWO-Flanders (Research Foundation – Flanders), Grant 11V8915N. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the FWO and the Flemish Government – department EWI.			Approved	Most recent IF: 4.123
	Call Number	PLASMANT @ plasmant @c:irua:150357			Serial	4916
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	Author	Bal, K.M.; Huygh, S.; Bogaerts, A.; Neyts, E.C.
	Title	Effect of plasma-induced surface charging on catalytic processes: application to CO₂activation			Type	A1 Journal article
	Year	2018	Publication	Plasma sources science and technology	Abbreviated Journal	Plasma Sources Sci T
	Volume	27	Issue	2	Pages	024001
	Keywords	A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	Understanding the nature and effect of the multitude of plasma–surface interactions in plasma catalysis is a crucial requirement for further process development and improvement. A particularly intriguing and rather unique property of a plasma-catalytic setup is the ability of the plasma to modify the electronic structure, and hence chemical properties, of the catalyst through charging, i.e. the absorption of excess electrons. In this work, we develop a quantum chemical model based on density functional theory to study excess negative surface charges in a heterogeneous catalyst exposed to a plasma. This method is specifically applied to investigate plasma-catalytic CO2 activation on supported M/Al2O3 (M=Ti, Ni, Cu) single atom catalysts. We find that (1) the presence of a negative surface charge dramatically improves the reductive power of the catalyst, strongly promoting the splitting of CO2 to CO and oxygen, and (2) the relative activity of the investigated transition metals is also changed upon charging, suggesting that controlled surface charging is a powerful additional parameter to tune catalyst activity and selectivity. These results strongly point to plasma-induced surface charging of the catalyst as an important factor contributing to the plasma-catalyst synergistic effects frequently reported for plasma catalysis.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000424520100001	Publication Date	2018-02-07
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1361-6595	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	3.302	Times cited	19	Open Access	OpenAccess
	Notes	KMB is funded as PhD fellow (aspirant) of the FWO-Flanders (Research Foundation—Flanders), Grant 11V8915N. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the FWO and the Flemish Government— department EWI.			Approved	Most recent IF: 3.302
	Call Number	PLASMANT @ plasmant @c:irua:149285			Serial	4813
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	Author	Neyts, E.C.; Bal, K.M.
	Title	Effect of electric fields on plasma catalytic hydrocarbon oxidation from atomistic simulations			Type	A1 Journal article
	Year	2017	Publication	Plasma processes and polymers	Abbreviated Journal	Plasma Process Polym
	Volume	14	Issue	6	Pages	e1600158
	Keywords	A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	The catalytic oxidative dehydrogenation of hydrocarbons is an industrially important process, in which selectivity is a key issue. We here investigate the conversion of methanol to formaldehyde on a vanadia surface employing long timescale simulations, reaching a time scale of seconds. In particular, we compare the thermal process to the case where an additional external electric field is applied, as would be the case in a direct plasma-catalysis setup. We find that the electric field influences the retention time of the molecules at the catalyst surface. These simulations provide an atomic scale insight in the thermal catalytic oxidative dehydrogenation process, and in how an external electric field may affect this process.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Weinheim	Editor
	Language		Wos	000403699900013	Publication Date	2016-11-08
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1612-8850	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.846	Times cited	2	Open Access	Not_Open_Access
	Notes				Approved	Most recent IF: 2.846
	Call Number	UA @ lucian @ c:irua:144210			Serial	4647
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	Author	Bal, K.M.; Cautereels, J.; Blockhuys, F.
	Title	Structures and spectroscopic properties of sulfur-nitrogen-pnictogen chains : R₂P-N=S=N-PR₂ and R₂P-N=S=N-AsR₂			Type	A1 Journal article
	Year	2017	Publication	Journal of molecular structure	Abbreviated Journal	J Mol Struct
	Volume	1132	Issue		Pages	102-108
	Keywords	A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	The conformational and configurational preferences of Me2PNSNPMe2 (3) and Me2PNSNAsMe2 (4) have been identified using quantum chemical calculations at the DFT/B3LYP/6-311+G* level of theory. An approach in which energetic, structural (geometries and bond orders), electronic (analysis of the electron density) and spectroscopic properties are combined leads to the conclusion that these sulfur-nitrogen-pnictogen chains share many of the properties of their chalcogen-nitrogen analogues but that the through-space intramolecular interactions favouring the Z,Z configuration are even weaker than in these latter compounds. The results of this analysis also lead to an unambiguous assignment of the variable-temperature 31P and 15N NMR spectra of these compounds and their structures both in solution and in the solid state.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Amsterdam	Editor
	Language		Wos	000393254400015	Publication Date	2016-08-07
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0022-2860	ISBN		Additional Links	UA library record; WoS full record
	Impact Factor	1.753	Times cited		Open Access	Not_Open_Access: Available from 03.10.2019
	Notes				Approved	Most recent IF: 1.753
	Call Number	UA @ lucian @ c:irua:145533			Serial	4726
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	Author	Bal, K.M.; Neyts, E.C.
	Title	Direct observation of realistic-temperature fuel combustion mechanisms in atomistic simulations			Type	A1 Journal article
	Year	2016	Publication	Chemical science	Abbreviated Journal	Chem Sci
	Volume	7	Issue	7	Pages	5280-5286
	Keywords	A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	Atomistic simulations can in principle provide an unbiased description of all mechanisms, intermediates, and products of complex chemical processes. However, due to the severe time scale limitation of conventional simulation techniques, unrealistically high simulation temperatures are usually applied, which are a poor approximation of most practically relevant low-temperature applications. In this work, we demonstrate the direct observation at the atomic scale of the pyrolysis and oxidation of n-dodecane at temperatures as low as 700 K through the use of a novel simulation technique, collective variable-driven hyperdynamics (CVHD). A simulated timescale of up to 39 seconds is reached. Product compositions and dominant mechanisms are found to be strongly temperature-dependent, and are consistent with experiments and kinetic models. These simulations provide a first atomic-level look at the full dynamics of the complicated fuel combustion process at industrially relevant temperatures and time scales, unattainable by conventional molecular dynamics simulations.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000380893900059	Publication Date	2016-05-05
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	2041-6520	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	8.668	Times cited	22	Open Access
	Notes	K. M. B. is funded as PhD fellow (aspirant) of the FWO-Flanders (Fund for Scientic Research-Flanders), Grant 11V8915N. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), funded by the Hercules Foundation and the Flemish Government – department EWI. The authors would also like to thank S. Banerjee for assisting with the interpretation of the experimental results.			Approved	Most recent IF: 8.668
	Call Number	c:irua:134577 c:irua:135670			Serial	4105
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	Author	Bal, K.M.; Neyts, E.C.
	Title	Merging Metadynamics into Hyperdynamics: Accelerated Molecular Simulations Reaching Time Scales from Microseconds to Seconds			Type	A1 Journal article
	Year	2015	Publication	Journal of chemical theory and computation	Abbreviated Journal	J Chem Theory Comput
	Volume	11	Issue	11	Pages	4545-4554
	Keywords	A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	The hyperdynamics method is a powerful tool to simulate slow processes at the atomic level. However, the construction of an optimal hyperdynamics potential is a task that is far from trivial. Here, we propose a generally applicable implementation of the hyperdynamics algorithm, borrowing two concepts from metadynamics. First, the use of a collective variable (CV) to represent the accelerated dynamics gives the method a very large flexibility and simplicity. Second, a metadynamics procedure can be used to construct a suitable history-dependent bias potential on-the-fly, effectively turning the algorithm into a self-learning accelerated molecular dynamics method. This collective variable-driven hyperdynamics (CVHD) method has a modular design: both the local system properties on which the bias is based, as well as the characteristics of the biasing method itself, can be chosen to match the needs of the considered system. As a result, system-specific details are abstracted from the biasing algorithm itself, making it extremely versatile and transparent. The method is tested on three model systems: diffusion on the Cu(001) surface and nickel-catalyzed methane decomposition, as examples of reactive processes with a bond-length-based CV, and the folding of a long polymer-like chain, using a set of dihedral angles as a CV. Boost factors up to 109, corresponding to a time scale of seconds, could be obtained while still accurately reproducing correct dynamics.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000362921700004	Publication Date	2015-09-02
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1549-9618	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	5.245	Times cited	41	Open Access
	Notes	K.M.B. is funded as Ph.D. fellow (aspirant) of the FWOFlanders (Fund for Scientific Research-Flanders), Grant No. 11 V8915N. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), funded by the Hercules Foundation and the Flemish Government−Department EWI.			Approved	Most recent IF: 5.245; 2015 IF: 5.498
	Call Number	c:irua:128183			Serial	3991
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	Author	Bal, K.M.; Neyts, E.C.
	Title	On the time scale associated with Monte Carlo simulations			Type	A1 Journal article
	Year	2014	Publication	The journal of chemical physics	Abbreviated Journal	J Chem Phys
	Volume	141	Issue	20	Pages	204104
	Keywords	A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	Uniform-acceptance force-bias Monte Carlo (fbMC) methods have been shown to be a powerful technique to access longer timescales in atomistic simulations allowing, for example, phase transitions and growth. Recently, a new fbMC method, the time-stamped force-bias Monte Carlo (tfMC) method, was derived with inclusion of an estimated effective timescale; this timescale, however, does not seem able to explain some of the successes the method. In this contribution, we therefore explicitly quantify the effective timescale tfMC is able to access for a variety of systems, namely a simple single-particle, one-dimensional model system, the Lennard-Jones liquid, an adatom on the Cu(100) surface, a silicon crystal with point defects and a highly defected graphene sheet, in order to gain new insights into the mechanisms by which tfMC operates. It is found that considerable boosts, up to three orders of magnitude compared to molecular dynamics, can be achieved for solid state systems by lowering of the apparent activation barrier of occurring processes, while not requiring any system-specific input or modifications of the method. We furthermore address the pitfalls of using the method as a replacement or complement of molecular dynamics simulations, its ability to explicitly describe correct dynamics and reaction mechanisms, and the association of timescales to MC simulations in general.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	New York, N.Y.	Editor
	Language		Wos	000345641400005	Publication Date	2014-11-26
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0021-9606;1089-7690;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	2.965	Times cited	26	Open Access
	Notes				Approved	Most recent IF: 2.965; 2014 IF: 2.952
	Call Number	UA @ lucian @ c:irua:120667			Serial	2459
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	Author	Somers, W.; Bogaerts, A.; van Duin, A.C.T.; Huygh, S.; Bal, K.M.; Neyts, E.C.
	Title	Temperature influence on the reactivity of plasma species on a nickel catalyst surface : an atomic scale study			Type	A1 Journal article
	Year	2013	Publication	Catalysis today	Abbreviated Journal	Catal Today
	Volume	211	Issue		Pages	131-136
	Keywords	A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	In recent years, the potential use of hydrogen as a clean energy source has gained considerable attention. Especially H2 formation by Ni-catalyzed reforming of methane at elevated temperatures is an attractive process. However, a more fundamental knowledge at the atomic level is needed for a full comprehension of the reactions at the catalyst surface. In this contribution, we therefore investigate the H2 formation after CHx impacts on a Ni(1 1 1) surface in the temperature range 4001600 K, by means of reactive molecular dynamics (MD) simulations using the ReaxFF potential. While some H2 formation is already observed at the lower temperatures, substantial H2 formation is only obtained at elevated temperatures of 1400 K and above. At 1600 K, the H2 molecules are even the most frequently formed species. In direct correlation with the increasing dehydrogenation at elevated temperatures, an increased surface-to-subsurface C-diffusivity is observed as well. This study highlights the major importance of the temperature on the H2 formation.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication	Amsterdam	Editor
	Language		Wos	000320697800020	Publication Date	2013-03-25
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	0920-5861;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	4.636	Times cited	27	Open Access
	Notes				Approved	Most recent IF: 4.636; 2013 IF: 3.309
	Call Number	UA @ lucian @ c:irua:108675			Serial	3500
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	Author	Neyts, E.C.; Thijsse, B.J.; Mees, M.J.; Bal, K.M.; Pourtois, G.
	Title	Establishing uniform acceptance in force biased Monte Carlo simulations			Type	A1 Journal article
	Year	2012	Publication	Journal of chemical theory and computation	Abbreviated Journal	J Chem Theory Comput
	Volume	8	Issue	6	Pages	1865-1869
	Keywords	A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
	Abstract	Uniform acceptance force biased Monte Carlo (UFMC) simulations have previously been shown to be a powerful tool to simulate atomic scale processes, enabling one to follow the dynamical path during the simulation. In this contribution, we present a simple proof to demonstrate that this uniform acceptance still complies with the condition of detailed balance, on the condition that the characteristic parameter lambda = 1/2 and that the maximum allowed step size is chosen to be sufficiently small. Furthermore, the relation to Metropolis Monte Carlo (MMC) is also established, and it is shown that UFMC reduces to MMC by choosing the characteristic parameter lambda = 0 [Rao, M. et al. Mol. Phys. 1979, 37, 1773]. Finally, a simple example compares the UFMC and MMC methods.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000305092400002	Publication Date	2012-05-16
	Series Editor		Series Title		Abbreviated Series Title
	Series Volume		Series Issue		Edition
	ISSN	1549-9618;1549-9626;	ISBN		Additional Links	UA library record; WoS full record; WoS citing articles
	Impact Factor	5.245	Times cited	20	Open Access
	Notes				Approved	Most recent IF: 5.245; 2012 IF: 5.389
	Call Number	UA @ lucian @ c:irua:99090			Serial	1082
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