Variational time-dependent Hartree–Fock calculations. I. Applications to four-electron atomic and molecular systems

Abstract
Solutions of the time‐dependent Hartree–Fock (TDHF) equations are obtained by a variational treatment that employs Slater basis sets. Application is made to several four‐electron atomic and molecular systems. For the beryllium isoelectronic sequence the variational approach is comparable in accuracy to numerical integrations of the TDHF equations. It provides also a description of the resonances that arise from excitation of the inner‐shell electrons. Similar calculations for the molecule LiH show that the TDHF method is capable of producing accurate oscillator strengths for molecular systems. Results are given for LiH and for the isoelectronic BeH+ molecule.