dipolmol 1.1.1

DiPolMol: tools for calculating molecular dipole moments, polarisabilities, and Hamiltonians

DiPolMol-Py

A Python package to calculate the rotational and hyperfine structure of doublet-Sigma molecules (e.g., CaF, BaF, SrF) in the presence of external fields.

DiPolMol-Py is licensed under a BSD 3 clause license, a copy can be found `See the LICENSE file'. If you use our work for academic purposes you can cite us using:

B.Humphreys et al. DiPolMol-Py: A Python package for calculations for $^{2}{\Sigma}$ ground-state molecules (https://arxiv.org/pdf/2503.21663).

Installation

run: pip install dipolmol

This installs the latest stable release and all required dependencies.

Package structure

Programme Files:

Hamiltonian – used to build the required Hamiltonian using matrix representation, including the field-free Hamiltonian and in the presence of magnetic, dc electric and off-resonant light fields.

Calculate – uses the eigenstates and eigenenergies found from diagonalising the Hamiltonian to run various calculations. Can be used to identify quantum numbers of eigenstates, calculate transition dipole moments and polarisabilities.

Constants – includes all known constants for CaF, BaF and SrF.

Examples:

There are three example files for calculating the energy structure in the presence of a magnetic, off-resonant light and electric field (example_Bfield, example_ac_Efield, example_dc_Efield).

There are two files to calculate the electric and magnetic moments of states (example_electric_moment, example_magnetic_moment).

We provide example_polarisability to calculate the polarisability for a given wavelength and polarisation of light.

Finally, example_tdm can be used to calculate the transition dipole moment.

Example

.. code-block:: python

import numpy as np
import dipolmol.hamiltonian as hamiltonian
import dipolmol.calculate as calc
from dipolmol.constants import SrF

Nmax=4 #Identify the maximum N 
H0,H_B,H_dc,H_ac 
	= hamiltonian.build
		(Nmax,SrF,zeeman=True,Edc=False
          ,Eac=False) 

B = np.linspace(0,100,5000)*1e-4 #Tesla

H = H_0[..., None] + H_B[..., None]*B
H = H.transpose(2,0,1)

energies, states, label_list = 
   calc.solve(H, Nmax, SrF,label=True, B)

Resulting plot of above code

.. image:: Images/zeeman_SrF_plot.png :width: 400 :alt: Resulting plot of above example

For more examples of usage, see the ./Examples module.