Low-lying electronic states of CuN calculated by MRCI method

The high accuracy ab initio calculation method of multi-reference configuration interaction (MRCI) is used to compute the low-lying eight electronic states of CuN. The potential energy curves (PECs) of the X³Σ^-, 1³Π, 2³Σ^-, 1³Δ, 1¹Δ, 1¹Σ^-, 1¹Π, and ⁵Σ^- in a range of R=0.1 nm-0.5 nm are obtained and they are goodly asymptotes to the Cu(²S_g )+N(⁴S_u) and Cu(²S_g)+N(²D_u) dissociation limits. All the possible vibrational levels, rotational constants, and spectral constants for the six bound states of X³Σ^-, 1³Π, 2³Σ^-, 1¹Δ, 1¹Σ^-, and 1¹Π are obtained by solving the radial Schrödinger equation of nuclear motion with Le Roy provided Level8.0 program. Also the transition dipole moments from the ground state X³Σ^- to the excited states 1³Π and 2³Σ^- are calculated and the result indicates that the 2³Σ^--X³Σ ^- transition has much higher transition dipole moment than the 1³Π-X³Σ^- transition even though the 1³Π state is much lower in energy than the 2³Σ^- state.