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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	Nikolaev, A.V.; Lamoen, D.; Partoens, B.
	Title	Extension of the basis set of linearized augmented plane wave (LAPW) method by using supplemented tight binding basis functions			Type	A1 Journal article
	Year	2016	Publication	The journal of chemical physics	Abbreviated Journal	J Chem Phys
	Volume	145	Issue	145	Pages	014101
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
	Abstract	In order to increase the accuracy of the linearized augmented plane wave (LAPW) method, we present a new approach where the plane wave basis function is augmented by two different atomic radial components constructed at two different linearization energies corresponding to two different electron bands (or energy windows). We demonstrate that this case can be reduced to the standard treatment within the LAPW paradigm where the usual basis set is enriched by the basis functions of the tight binding type, which go to zero with zero derivative at the sphere boundary. We show that the task is closely related with the problem of extended core states which is currently solved by applying the LAPW method with local orbitals (LAPW+LO). In comparison with LAPW+LO, the number of supplemented basis functions in our approach is doubled, which opens up a new channel for the extension of the LAPW and LAPW+LO basis sets. The appearance of new supplemented basis functions absent in the LAPW+LO treatment is closely related with the existence of the ul-component in the canonical LAPW method. We discuss properties of additional tight binding basis functions and apply the extended basis set for computation of electron energy bands of lanthanum (face and body centered structures) and hexagonal close packed lattice of cadmium. We demonstrate that the new treatment gives lower total energies in comparison with both canonical LAPW and LAPW+LO, with the energy difference more pronounced for intermediate and poor LAPW basis sets.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000379584700003	Publication Date	2016-07-05
	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	11	Open Access
	Notes	A.V.N. acknowledges useful discussions with B. Verberck, E. V. Tkalya, and A. V. Bibikov.			Approved	Most recent IF: 2.965
	Call Number	c:irua:134290			Serial	4099
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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	Payne, L.M.; Masia, F.; Zilli, A.; Albrecht, W.; Borri, P.; Langbein, W.
	Title	Quantitative morphometric analysis of single gold nanoparticles by optical extinction microscopy: Material permittivity and surface damping effects			Type	A1 Journal article
	Year	2021	Publication	Journal Of Chemical Physics	Abbreviated Journal	J Chem Phys
	Volume	154	Issue	4	Pages	044702
	Keywords	A1 Journal article; Electron microscopy for materials research (EMAT)
	Abstract
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000630495600001	Publication Date	2021-01-28
	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	This work was supported by the Welsh Government Life Sciences Bridging Fund (Grant No. LSBF/R6-005), the UK EPSRC (Grant Nos. EP/I005072/1 and EP/M028313/1), and the European Commission (Grant No. EUSMI E191000350). P.B. acknowledges the Royal Society for her Wolfson research merit award (Grant No. WM140077). F.M. acknowledges the Ser Cymru II programme (Case ID 80762-CU-148) which is part-funded by Cardiff University and the European Regional Development Fund through the Welsh Government. W.A. acknowledges an Individual Fellowship from the Marie Skłodowska-Curie actions (MSCA) under the EU’s Horizon 2020 program (Grant No. 797153, SOPMEN) and Sara Bals for supporting the STEM measurements. The brightfield TEM was performed by Thomas Davies at Cardiff University. We acknowledge Iestyn Pope for technical support of the optical equipment.			Approved	Most recent IF: 2.965
	Call Number	EMAT @ emat @c:irua:177566			Serial	6748
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	Author	Hamid, I.; Jalali, H.; Peeters, F.M.; Neek-Amal, M.
	Title	Abnormal in-plane permittivity and ferroelectricity of confined water : from sub-nanometer channels to bulk			Type	A1 Journal article
	Year	2021	Publication	Journal Of Chemical Physics	Abbreviated Journal	J Chem Phys
	Volume	154	Issue	11	Pages	114503
	Keywords	A1 Journal article; Condensed Matter Theory (CMT)
	Abstract	Dielectric properties of nano-confined water are important in several areas of science, i.e., it is relevant in the dielectric double layer that exists in practically all heterogeneous fluid-based systems. Molecular dynamics simulations are used to predict the in-plane dielectric properties of confined water in planar channels of width ranging from sub-nanometer to bulk. Because of suppressed rotational degrees of freedom near the confining walls, the dipole of the water molecules tends to be aligned parallel to the walls, which results in a strongly enhanced in-plane dielectric constant (epsilon (parallel to)) reaching values of about 120 for channels with height 8 angstrom < h < 10 angstrom. With the increase in the width of the channel, we predict that epsilon (parallel to) decreases nonlinearly and reaches the bulk value for h > 70 angstrom. A stratified continuum model is proposed that reproduces the h > 10 angstrom dependence of epsilon (parallel to). For sub-nanometer height channels, abnormal behavior of epsilon (parallel to) is found with two orders of magnitude reduction of epsilon (parallel to) around h similar to 7.5 angstrom, which is attributed to the formation of a particular ice phase that exhibits long-time (similar to mu s) stable ferroelectricity. This is of particular importance for the understanding of the influence of confined water on the functioning of biological systems.
	Address
	Corporate Author				Thesis
	Publisher		Place of Publication		Editor
	Language		Wos	000629831900001	Publication Date	2021-03-17
	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	13	Open Access	OpenAccess
	Notes				Approved	Most recent IF: 2.965
	Call Number	UA @ admin @ c:irua:177579			Serial	6967
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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	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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