Krylov Subspace Method for Molecular Dynamics Simulation based on Large-Scale Electronic Structure Theory

TL;DR

This paper introduces a Krylov subspace method for large-scale electronic structure calculations that efficiently computes the density matrix, enabling accurate molecular dynamics simulations of surface reconstructions.

Contribution

It presents a novel Krylov subspace approach to calculate the density matrix without eigenstates, improving efficiency in large-scale electronic structure simulations.

Findings

Converges reliably within a limited basis set

Accurately reproduces surface reconstruction mechanisms

Calculates energy, force, density of states, and energy spectrum

Abstract

For large scale electronic structure calculation, the Krylov subspace method is introduced to calculate the one-body density matrix instead of the eigenstates of given Hamiltonian. This method provides an efficient way to extract the essential character of the Hamiltonian within a limited number of basis set. Its validation is confirmed by the convergence property of the density matrix within the subspace. The following quantities are calculated; energy, force, density of states, and energy spectrum. Molecular dynamics simulation of Si(001) surface reconstruction is examined as an example, and the results reproduce the mechanism of asymmetric surface dimer.