pyckett 0.1.14

A wrapper around Pickett's SPFIT and SPCAT

Pyckett

Pyckett is a python wrapper around the SPFIT/SPCAT package (H. M. Pickett, "The Fitting and Prediction of Vibration-Rotation Spectra with Spin Interactions," J. Mol. Spectrosc. 148, 371-377 (1991)).

Install the package with pip by using the following command

pip install pyckett

If SPFIT and SPCAT cannot be executed via the commands spfit and spcat (if they are not in your PATH or have different names) point to them by setting the PYCKETT_SPFIT_PATH and PYCKETT_SPCAT_PATH environment variables to their full paths.

Documentation

Currently, the documentation is limited to the docstrings of the main library. To easily access the docstrings you can run

pip install pdoc
pdoc pyckett

after having installed Pyckett.

The CLI tools provide help texts via the -h or --help flags.

CLI Tools

Pyckett provides a set of command line utilities which perform common steps of an iterative fitting process.

pyckett_add helps adding new parameters to the fit, pyckett_omit is used for evaluating which parameters can be omitted.

pyckett_separatefits can be used to separate a global fit into separate fits for each state.

pyckett_uncertainties evaluates the uncertainties of the parameters.

pyckett_partitionfunction calculates the partition function for different temperatures.

pyckett_auto automatically builds up the Hamiltonian step by step.

pyckett_fit and pyckett_cat are shortcuts to SPFIT and SPCAT, respectively.

See the respective help functions (by adding --help after the command) to see their syntax.

Examples

You can read files from the SPFIT/SPCAT universe with the following syntax

var_dict = pyckett.parvar_to_dict(r"path/to/your/project/molecule.var")
par_dict = pyckett.parvar_to_dict(r"path/to/your/project/molecule.par")
int_dict = pyckett.int_to_dict(r"path/to/your/project/molecule.int")
lin_df = pyckett.lin_to_df(r"path/to/your/project/molecule.lin")
cat_df = pyckett.cat_to_df(r"path/to/your/project/molecule.cat")
egy_df = pyckett.egy_to_df(r"path/to/your/project/molecule.egy")

erham_df = pyckett.erhamlines_to_df(r"path/to/your/project/molecule.in")

Finalize cat file

This function merges the cat and lin dataframes, sums up duplicate values in the cat file and allows to translate quantum numbers:

fin_cat_df, fin_lin_df = pyckett.finalize(cat_df, lin_df, qn_tdict, qn)

Find candidates for double-resonance measurements

This function finds possible transition arrangements for double-resonance measurements. Input two cat dataframes with the transitions that are in the range of your probe and pump source.

results_df = pyckett.get_dr_candidates(cat_df1, cat_df2)

Check Crossings

pyckett.check_crossings(egy_df, [1], range(10))

Plot Mixing Coefficients

pyckett.mixing_coefficient(egy_df, "qn4 == 1 and qn2 < 20 and qn1 < 20 and qn1==qn2+qn3")