Diatomic-py: A Python module for calculating the rotational and hyperfine structure of 1S molecules

We present a computer program to calculate the quantised rotational and hyperfine energy levels of (1)sigma diatomic molecules in the presence of dc electric, dc magnetic, and off-resonant optical fields. Our program is applicable to the bialkali molecules used in ongoing state-of-the-art experiments with ultracold molecular gases. We include functions for the calculation of space-fixed electric dipole moments, magnetic moments and transition dipole moments. Program summary Program Title: Diatomic-Py CPC Library link to program files: https://doi .org /10 .17632 /3yfxnh5bn5 .1 Developer's repository link: https://doi .org /10 .5281 /zenodo .6632148 Licensing provisions: BSD 3-clause Programming language: Python >= 3.7 Nature of problem: Calculation of the rotational and hyperfine structure of (1)sigma molecules in the presence of dc magnetic, dc electric, and off-resonant laser fields. Solution method: A matrix representation of the Hamiltonian is constructed in the uncoupled basis set. Eigenstates and eigenenergies are calculated by numerical diagonalization of the Hamiltonian.Additional comments including restrictions and unusual features: Restricted to calculating the Stark and Zeeman shifts with co-axial electric and magnetic fields. (C) 2022 The Author(s). Published by Elsevier B.V.

Automated summary

This article presents a computer program for calculating the quantized rotational and hyperfine energy levels of (1)sigma diatomic molecules in the presence of various fields. It is applicable to state-of-the-art experiments with ultracold molecular gases.