|   | 
Details
   web
Records
Author da Silva, A.L.C.; Candido, L.; Teixeira Rabelo, J.N.; Hai, G.-Q.; Peeters, F.M.
Title Anharmonic effects on thermodynamic properties of a graphene monolayer Type A1 Journal article
Year (down) 2014 Publication Europhysics letters Abbreviated Journal Epl-Europhys Lett
Volume 107 Issue 5 Pages 56004
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We extend the unsymmetrized self-consistent-field method (USF) for anharmonic crystals to layered non-Bravais crystals to investigate structural, dynamical and thermodynamic properties of a free-standing graphene monolayer. In this theory, the main anharmonicity of the crystal lattice has been included and the quantum corrections are taken into account in an h-expansion for the one-particle density matrix. The obtained result for the thermal expansion coefficient (TEC) of graphene shows a strong temperature dependence and agrees with experimental results by Bao et al. (Nat. Nanotechnol., 4 (2009) 562). The obtained value of TEC at room temperature (300 K) is -6.4 x 10(- 6) K- 1 and it becomes positive for T > T-alpha = 358K. We find that quantum effects are significant for T < 1000 K. The interatomic distance, effective amplitudes of the graphene lattice vibrations, adiabatic and isothermal bulk moduli, isobaric and isochoric heat capacities are also calculated and their temperature dependences are determined. Copyright (C) EPLA, 2014
Address
Corporate Author Thesis
Publisher Place of Publication Paris Editor
Language Wos 000341559900020 Publication Date 2014-09-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0295-5075;1286-4854; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.957 Times cited 23 Open Access
Notes ; This research was supported by the Brazilian agencies CNPq, FAPEG and FAPESP, the Flemish Science Foundation (FWO-Vl) and the Methusalem Foundation of the Flemish Government. ; Approved Most recent IF: 1.957; 2014 IF: 2.095
Call Number UA @ lucian @ c:irua:119289 Serial 118
Permanent link to this record
 

 
Author Brito, B.G.A.; Hai, G.-Q.; Teixeira Rabelo, J.N.; Cândido, L.
Title A quantum Monte Carlo study on electron correlation in all-metal aromatic clusters MAl4 – (M = Li, Na, K, Rb, Cu, Ag and Au) Type A1 Journal article
Year (down) 2014 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys
Volume 16 Issue 18 Pages 8639-8645
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Using fixed-node diffusion quantum Monte Carlo (FN-DMC) simulation we investigate the electron correlation in all-metal aromatic clusters MAl4- (with M = Li, Na, K, Rb, Cu, Ag and Au). The electron detachment energies and electron affinities of the clusters are obtained. The vertical electron detachment energies obtained from the FN-DMC calculations are in very good agreement with the available experimental results. Calculations are also performed within the Hartree-Fock approximation, density-functional theory (DFT), and the couple-cluster (CCSD(T)) method. From the obtained results, we analyse the impact of the electron correlation effects in these bimetallic clusters and find that the correlation of the valence electrons contributes significantly to the detachment energies and electron affinities, varying between 20% and 50% of their total values. Furthermore, we discuss the electron correlation effects on the stability of the clusters as well as the accuracy of the DFT and CCSD(T) calculations in the present systems.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000334602900052 Publication Date 2014-03-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1463-9076;1463-9084; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited 10 Open Access
Notes ; This research was supported by CNPq, FAPESP and FAPEG (Brazil). ; Approved Most recent IF: 4.123; 2014 IF: 4.493
Call Number UA @ lucian @ c:irua:117247 Serial 2781
Permanent link to this record