epdfsuite.calibration

Functions

build_calibration_data_from_cif(cif_file, ...)

Generate a list of diffraction peaks from a CIF structure file.

get_calibration_parameters(poni_file)

Extract calibration parameters from a PONI file generated by pyFAI-calib2.

perform_geometric_calibration(cif_file, ...)

Perform geometric calibration of electron diffraction data using pyFAI-calib2.
epdfsuite.calibration.build_calibration_data_from_cif(cif_file, wavelength, n_peaks=15, two_theta_range=(0, 2))[source]

Generate a list of diffraction peaks from a CIF structure file.

Uses pymatgen’s XRD calculator to compute the simulated diffraction pattern, then exports the d-spacings to a text file (distances.txt) for use by pyFAI-calib2.

Parameters:

  • cif_file (str) – Path to the CIF structure file.

  • wavelength (float) – Electron (or X-ray) wavelength in Å.

  • n_peaks (int, optional) – Maximum number of peaks to return. Default is 15.

  • two_theta_range (tuple of float, optional) – Angular range in degrees (2θ_min, 2θ_max) used to filter peaks. Default is (0, 2).

Returns:

peaks (list of dict) – Each element contains:

  • 'hkl': Miller indices

  • 'd': d-spacing in Å

  • 'two_theta': Bragg angle in degrees

  • 'intensity': relative intensity

epdfsuite.calibration.perform_geometric_calibration(cif_file, image_file, mtf_file=None)[source]

Perform geometric calibration of electron diffraction data using pyFAI-calib2.

Exports the image as a temporary EDF file, optionally applies MTF deconvolution, computes calibrant d-spacings from the CIF, prints the instrument settings to enter in pyFAI-calib2, and launches the calibration GUI.

Parameters:

  • cif_file (str) – Path to the CIF structure file of the calibrant.

  • image_file (str) – Path to the DM4 image file of the calibrant diffraction pattern.

  • mtf_file (str, optional) – Path to the MTF file. If provided, Wiener deconvolution is applied to the image before calibration.

epdfsuite.calibration.get_calibration_parameters(poni_file)[source]

Extract calibration parameters from a PONI file generated by pyFAI-calib2.

Parameters:

poni_file (str) – Path to the PONI file produced after calibration.

Returns:

calibration_params (dict) – Dictionary containing the following keys (when present in the file):

  • 'distance': sample-to-detector distance (m)

  • 'poni1', 'poni2': point of normal incidence coordinates (m)

  • 'rot1', 'rot2', 'rot3': detector rotation angles (rad)

  • 'wavelength': wavelength (m)

  • 'pixel1', 'pixel2': pixel sizes (m)

  • 'max_shape': detector shape in pixels