The spectroscopic and molecular constants of low-lying excited states of MgCl molecule by multi-reference configuration interaction method

The potential energy curves of five Λ-S states have been computed by high - level multi - reference configuration interaction method with all-electron aug-cc-pwCV5Z + DK basis set. In order to obtain high precise spectroscopic properties, Davidson modification, the core valence correlation and relativistic correction are introduced in the calculation. Based on the PECs of 5 Λ-S states, the accurate spectroscopic constants, vibration levels and molecular constants of bound states are obtained by solving the radial Schroedinger equation. Compared with the recent theoretical calculation, the present values are closer to the experimental data. These results show that the high precision calculation method and the correlation correction are necessary for analysis of spectral properties. It may be provided theory support for further researching on the spectroscopic and transition characters of higher excited states of MgCl molecule. (authors)