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

Journal article

We present a computer program to calculate the quantised rotational and hyperfine energy levels of 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 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.

Authors: Blackmore, JA; Gregory, PD; Hutson, JM; Cornish, SL

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Elsevier
• Journal: Computer Physics Communications
• Volume: 282
• Article number: 108512
• Publication date: 2022-08-29
• Acceptance date: 2022-08-22
• DOI: 10.1016/j.cpc.2022.108512
• ISSN: 0010-4655
• Language: English
• Keywords: hyperfine; molecules; FFR; Stark effect; Zeeman effect; Hamiltonian