Acceleration Schemes for Ab-Initio Molecular Dynamics and Electronic Structure Calculations

Details Acceleration Schemes for Ab-Initio Molecular Dynamics and Electronic Structure Calculations Acceleration Schemes for Ab-Initio Molecular Dynamics and Electronic Structure Calculations

1994-08-23

arxiv.org/abs/cond-mat/9408070v1

Physics

Condensed Matter

RevTex, 9 figures available upon request, to appear in Phys. Rev. B

Scientific paper

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 analyse 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 large wavevector components of the kinetic energy or from the small wavevector components of the Coulomb potential giving rise to the so called {\it charge sloshing} problem. We show how to eliminate large wavevector instabilities by adopting a preconditioning scheme that is implemented here for the first-time 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.

Affiliated with

Also associated with

No associations

Rating

Acceleration Schemes for Ab-Initio Molecular Dynamics and Electronic Structure Calculations does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Acceleration Schemes for Ab-Initio Molecular Dynamics and Electronic Structure Calculations, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Acceleration Schemes for Ab-Initio Molecular Dynamics and Electronic Structure Calculations will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-40021