Symmetry breaking in the molecular-dynamics method for ab initio total-energy calculations

An analysis of the symmetry of the electron wave functions as they evolve under the molecular-dynamics equation of motion is presented. It is found that symmetry in the initial conditions, corresponding to wave functions of two or more bands being partner functions, can prevent wave functions from converging to eigenfunctions of the Hamiltonian. This artificial symmetry is broken by the Gram-Schmidt orthogonalization procedure so any convenient initial conditions will lead to convergence to eigenstates of the Hamiltonian.