Extended Lagrangian Born-Oppenheimer molecular dynamics with dissipation
2009 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 130, no 21, 214109- p.Article in journal (Refereed) Published
Stability and dissipation in the propagation of the electronic degrees of freedom in time-reversible extended Lagrangian Born-Oppenheimer molecular dynamics [Niklasson , Phys. Rev. Lett. 97, 123001 (2006); Phys. Rev. Lett. 100, 123004 (2008)] are analyzed. Because of the time-reversible propagation the dynamics of the extended electronic degrees of freedom is lossless with no dissipation of numerical errors. For long simulation times under "noisy" conditions, numerical errors may therefore accumulate to large fluctuations. We solve this problem by including a dissipative external electronic force that removes noise while keeping the energy stable. The approach corresponds to a Langevin-like dynamics for the electronic degrees of freedom with internal numerical error fluctuations and external, approximately energy conserving, dissipative forces. By tuning the dissipation to balance the numerical fluctuations the external perturbation can be kept to a minimum.
Place, publisher, year, edition, pages
2009. Vol. 130, no 21, 214109- p.
ab initio calculations, fluctuations, molecular dynamics method
IdentifiersURN: urn:nbn:se:kth:diva-26991DOI: 10.1063/1.3148075ISI: 000266674400010ScopusID: 2-s2.0-67249126946OAI: oai:DiVA.org:kth-26991DiVA: diva2:373823
QC 201012012010-12-012010-12-012012-03-23Bibliographically approved