Acceleration schemes for <i>ab initio</i> molecular-dynamics simulations and electronic-structure calculations

Article Article scientifique Article Acceleration schemes for <i>ab initio</i> molecular-dynamics simulations and electronic-structure calculations eng 1994 author Tassone F. author Mauri Francesco 28361 author Car Roberto 27190 10561-10573 10.1103/PhysRevB.50.10561 1098-0121 https://link.aps.org/doi/10.1103/PhysRevB.50.10561 We study the convergence and the stability of fictitious dynamical methods for electrons. first, we show that a particular damped second-order dynamics has a much faster rate of convergence to the ground state than first-order steepest-descent algorithms while retaining their numerical cost per time step. Our damped dynamics has efficiency comparable to that of conjugate gradient methods in typical electronic minimization problems. Then, we analyze the factors that limit the size of the integration time step in approaches based on plane-wave expansions. The maximum allowed time step is dictated by the highest frequency components of the fictitious electronic dynamics. These can result either from the larger wave vector components of the kinetic energy or from the small wave vector components of the Coulomb potential giving rise to the so called charge sloshing problem. We show how to eliminate large wave vector instabilities by adopting a preconditioning scheme in the context of Car-Parrinello ab initio molecular-dynamics simulations of the ionic motion. We also show how to solve the charge sloshing problem when this is present. We substantiate our theoretical analysis with numerical tests on a number of different silicon and carbon systems having both insulating and metallic character. Dewey 500.2 33 Département de physique de la matière quantique 131 false Physical Review. B, Condensed Matter 50 15 ea298493-bf74-46ae-94fe-c650007fd535 Article (Published version) Restricted PhysRevB.50.10561.pdf 752643 application/pdf restrictedAccess Faculté des sciences / Section de physique / Département de physique de la matière quantique

Title	Published in	Year	Views	Downloads

First-Principles Study of Excitonic Self-Trapping in Diamond	Physical Review Letters	1995	189	215
Acceleration schemes for ab initio molecular-dynamics simulations and electronic-structure calculations	Physical Review. B, Condensed Matter	1994	365	0

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Mauri, Francesco