A full dimensional investigation of infrared spectroscopy of the RbCs dimer using the multi-configuration time-dependent Hartree method

摘要

The geometry and infrared absorption spectrum of (RbCs)_2 have been studied by full dimensional quantum dynamics simulations. For this purpose, the potential energy and dipole moment surfaces are generated by means of a cluster expansion with all two and three mode correlations, and fitted to analytical expressions with negligible deviations. Accordingly, the ground state (RbCs)_2 has a diamond geometry with D_(2h) symmetry. The infrared spectrum with frequencies up to 120 cm~(?1), exhibits rich details of the fundamentals, overtones, and combination bands; the highest fundamental frequency of (RbCs)_2 is only 40.26 cm~(?1). The present study unravels important details of the interactions between the widely investigated ultracold RbCs molecules.