Calculations of transition and permanent dipole moments of heteronuclear alkali dimers NaK, NaRb and NaCs

Abstract

Obtaining ultracold samples of dipolar molecules is a current challenge which requires an accurate knowledge of their electronic properties to guide the ongoing experiments. In this paper, we calculate permanent dipole moments and transition dipole moments for excited states for alkali dimers NaK, NaRb and NaCs using a standard quantum chemistry approach based on pseudopotentials for atomic core representation, Gaussian basis sets, and effective terms for core polarization effects. We provide an extensive set of data concerning transitions among the first seven molecular states of each symmetry ¹Σ⁺, ³Σ⁺, ¹Π, ³Π. The accuracy of our results is generally improved compared to previous similar calculations on NaK, while they are found to be in good agreement with the few NaRb states calculated with other methods. Results for NaCs transition dipole moments are given here for the first time.

Keywords:

• Alkali dimers
• Transition dipole moments
• Ultracold molecules
• Effective core polarization potential
• NaK
• NaRb
• NaCs