The multiconfiguration timehyphen;dependent Hartreendash;Fock method based on a closedhyphen;shellhyphen;type multiconfiguration selfminus;consistent field reference state and its application to the LiH molecule

摘要

The linear response calculations in the multiconfiguration timehyphen;dependent Hartreendash;Fock (MCTDHF) approximation with a closedhyphen;shellhyphen;type MCSCF state as the timehyphen;independent reference state are discussed. The application to the LiH molecule with a small basis set (lsqb;4s2p1d/2s1prsqb;) shows validity of our MCTDHF approach to the singlet ground state. Our MCSCF correlation energy is 97percnt; of the total (=full CI) correlation energy and the MCTDHF excitation energies are in good agreements with the Dgr; full CI excitation energies. The Bornndash;Oppenheimer potential energy curves for the lowest three singlet states of LiH and the corresponding vibrational level spacings, the transition moments, the oscillator strengths, and the frequencyhyphen;dependent dipole polarizabilities are reported. All of these results imply the potentiality of our MCTDHF method for the future work with the larger basis set. One of such basis sets (lsqb;9s8p4d/8s7p1drsqb;) is referentially used only at the singlehyphen;configuration TDHF level, and the resultant nearhyphen;Hartreendash;Fock polarizability and Thomasndash;Reichendash;Kuhn sum rule is very promising.