Structure and analytical potential energy function of the ground state of CuC and CuN molecules

Based on effective core potential of Cu atom, the LANL2DZ basis set for Cu atom and the 6-311+(d) basis set for C and N atoms were used. At the same time, the necessary modification was made for the section of p orbit function of valence electrons basis set of Cu atom. The energies, equilibrium structure, and harmonic frequency of the ground state of CuC and CuN molecules were calculated using density functional theory (B3LYP) method. Based on the theory of atomic and molecular statics, the reasonable dissociation limit and dissociation energy for the ground state of CuC and CuN molecules were derived. The potential energy curve scan for the ground state of CuC and CuN molecules was carried out with density function theory (B3LYP) method. Murrell-Sorbie analytical potential energy function and its Dunham expansion around equilibrium position were also derived with nonlinear least-square fit. At the same time, the spectroscopic constants for the ground state of CuC and CuN molecules were calculated following the formula of Herzberg and Dunham.