Ab initio calculation of the electronic structures of the (7)Sigma(+) ground and A (7)Pi and a (5)Sigma(+) excited states of MnH

作者：Tomonari Mutsumi^*; Nagashima Umpei; Hirano Tsuneo

来源：Journal of Chemical Physics, 2009, 130(15): 154105.

DOI：10.1063/1.3098917

• ab initio calculations
• configuration interactions
• excited states
• ground states
• manganese compounds
• molecular configurations
• rotational states
• SCF calculations

Electronic structures and molecular constants of the ground (7)Sigma(+) and low-lying A (7)Pi and a (5)Sigma(+) electronic excited states of the MnH molecule were studied by multireference single and double excitation configuration interaction (MR-SDCI) with Davidson's correction (+Q) calculations under exact C-infinity v symmetry using Slater-type basis sets. To correctly describe the (7)Sigma(+) electronic ground state, X (7)Sigma(+), at the MR-SDCI+Q calculation, we employed a large number of reference configurations in terms of the state-averaged complete active space self-consistent field (CASSCF) orbitals, taking into account the contribution from the B (7)Sigma(+) excited state. The A (7)Pi and a (5)Sigma(+) states can well be described by the MR-SDCI wave functions based on the CASSCF orbitals obtained for the lowest state only. In the MR-SDCI+Q, calculations of the X (7)Sigma(+), A (7)Pi, and a (5)Sigma(+) states required 16, 7, and 17 reference configurations, respectively. Molecular constants, i.e., r(e) and omega(e) of these states and excitation energy from the X (7)Sigma(+) state, obtained at the MR-SDCI+Q level, showed a good agreement with experimental values. The small remaining differences may be accounted for by taking relativistic effects into account.

• 出版日期2009-4-21