Time-dependent Hartree–Fock simulations of the dynamics of polyatomic molecules

The use of the time-dependent Hartree–Fock method for performing molecular-dynamics simulations of polyatomic systems is explored. The theory is outlined for closed-shell restricted Hartree–Fock wave functions which employ the neglect of diatomic differential overlap approximation. The motions of the nuclei are treated classically. If the starting electronic wave function for a simulation obeys the time-independent variational principle then trajectories calculated with the algorithm stay very close to those obtained with a method in which the wave function obeys the time-independent variational principle at all times.