Theoretical prediction on the structures of the HMgN- and HNMg- using multiconfigurational methods

The nine-valence-electron HMgN- and HNMg- have been investigated for the first time theoretically using complete active space self-consistent field (CASSCF) and multiconfiguration second-order perturbation theory (CASPT2) methods in conjunction with the contracted atomic natural orbital (ANO) basis sets. The structures of the low-lying electronic states of HMgN- and HNMg- were predicted. The possible unimolecular conversions between HMgN- and HNMg- were discussed. The calculated results indicated that the ground-state of HMgN- is linear, while the ground-state HNMg- is bent, which is in contradiction to the Walsh rules, which predict linear structures for HXY systems containing 10 or fewer valence electrons.