MRCI potential curve and analytical potential energy function of the ground state (1Σ+) of HgZn

The multireference configuration interaction (MRCI) method is used to calculate a set of energies at different internuclear distances and six different computational levels. Six potential energy curves (PECs) are obtained. Four of them are fitted to analytical potential energy functions (APEFs) using the Murrel-Sorbie potential function, because the dissociation energies and bond lengths of the other ones are obviously not in agreement with the experimental values. Based on the PECs, the vibrational levels are determined by solving Schrödinger equation of nuclear motion, and corresponding spectroscopic parameters are accurately calculated respectively. The values of equilibrium positions and dissociation energies we obtained are compared with other theory and experimental data available at present.