Molecular structure and properties of MgCa molecule

Abstract

• Investigation of 13 electronic states using MRCI approach with 4 basis sets. • New assignment of the experimental electronic states. • Spectroscopic and ro-vibrational constants with experimental comparisons. • Franck-Condon factors for vibronic transitions. • Vibrational Branching equipped with calculated lifetimes for laser cooling studies. Experimentally, when the MgCa molecule was studied, certain ambiguity occurred, and an ab initio calculation was requested. For this reason, an extensive study is carried out regarding the electronic structure of MgCa. A new and improved assignment of experimental molecular states is allocated. The accuracy of the adopted ab initio approach is proven in different aspects through our work when agreements are attained between two different experimental approaches and the present work. Theoretical studies of the MgCa compound are performed within the framework of the multi-reference configuration interaction method using 4 different basis sets in order to reach optimal accuracy. The potential energy curves, permanent dipole moments, spectroscopic constants ( T e , ω e , B e , and R e ), and ro-vibrational constants ( G v , B v , D v , R m i n , and R m a x ) are investigated for 13 electronic states. Nine new states are studied here for the first time. The Franck-Condon factors, transition dipole moments at R -centroid, vibrational branching including transition rates, and lifetimes are considered for the states required for laser cooling schemes. Since the focus of this study is devoted to an accurate description of the ground and lowest electronic excited states, we also constructed RKR potentials from the experimental Dunham-type coefficients and computed the spectroscopic and ro-vibrational constants for comparison sake.