Numerical stabilization of the first-principles molecular-dynamics method for metals.

Abstract

When applying the first-principles molecular-dynamics method to metals, it has been believed that the diagonalization of the one-electron Hamiltonian of the density-functional theory is necessary together with fractional occupation numbers during the minimization procedure of the total energy. It is shown that if we treat the occupation numbers of orbitals as independent variables in molecular dynamics, in addition to the electronic orbitals, the diagonalization is automatically attained and a new stable and efficient algorithm can be constructed.