Full configuration interaction benchmark calculations for TiH

Abstract

Full configuration interaction (FCI) results for the 3F and 5F states of Ti and the 4Phi and 2Delta states of TiH are presented. While the coupled pair functional (CPF) or modified CPF approaches are found to work well for the 4Phi state of TiH, they do not perform as well for the 2Delta state. Although for mu, the CASSCF/MRCI methods do well for the 2Delta state, when the active space is expanded outside the normal valence definition, the dipole moment is only brought into agreement with the FCI results by natural orbital iterations.