Spin–orbit coupling in a model Hamiltonian for d–d excited states of Ni2+ ion aqueous solution

The model effective Hamiltonian for electronic structure of Ni2+ aqueous solution [S. Iuchi, A. Morita, S. Kato, J. Chem. Phys. 121 (2004) 8446] is revised to include the spin–orbit coupling effects. In order to investigate the performance of the revised model Hamiltonian, the electronic absorption spectrum is computed through molecular dynamics simulations. The simulated spectrum is in a reasonable agreement with the experimental one including the band splitting originating from the spin–orbit coupling. This result indicates that the modified Hamiltonian reasonably describes the mixing of different spin states.