Fitting pd-neut-tof NCAF-WISH¶

This example shows how to refine the crystal structure parameters of Si from neutron diffraction data in a time-of-flight experiment performed on WISH diffractometer at ISIS.

Import EasyDiffraction¶

In [2]:

import easydiffraction as ed

import easydiffraction as ed

Create a job¶

Create a job — the main object to store all the information

In [3]:

job = ed.Job(type='tof')
print(job.type)

job = ed.Job(type='tof') print(job.type)

Job type: pd-tof-unp-1d-neut

Define a model¶

Download the CIF file from the EasyDiffraction repository on GitHub

In [4]:

ed.download_from_repository('ncaf.cif', destination='data')

ed.download_from_repository('ncaf.cif', destination='data')

Load a phase from the downloaded CIF file

In [5]:

job.add_phase_from_file('data/ncaf.cif')
print(job.phases)

job.add_phase_from_file('data/ncaf.cif') print(job.phases)

Collection of 1 phases: ['ncaf']

Show phase info in CIF format

In [6]:

phase = job.phases['ncaf']
print(phase.cif)

phase = job.phases['ncaf'] print(phase.cif)

data_ncaf
_cell_length_a 10.250256
_cell_length_b 10.250256
_cell_length_c 10.250256
_cell_angle_alpha 90.00000000
_cell_angle_beta 90.00000000
_cell_angle_gamma 90.00000000
_space_group_name_H-M_ref 'I 21 3'

loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
_atom_site_adp_type
_atom_site_B_iso_or_equiv
Ca Ca 0.4661 0.00000000 0.25 1.00000000 Biso 0.9
Al Al 0.25171 0.25171 0.25171 1.00000000 Biso 0.66
Na Na 0.08481 0.08481 0.08481 1.00000000 Biso 1.9
F1 F 0.1375 0.3053 0.1195 1.00000000 Biso 0.9
F2 F 0.3626 0.3634 0.1867 1.00000000 Biso 1.28
F3 F 0.4612 0.4612 0.4612 1.00000000 Biso 0.79

Display the crystal structure of a given model

In [7]:

job.show_crystal_structure(id='ncaf')

job.show_crystal_structure(id='ncaf')

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Define an experiment¶

Download the data file from the EasyDiffraction repository on GitHub

In [8]:

ed.download_from_repository('wish.xye', destination='data')

ed.download_from_repository('wish.xye', destination='data')

Show content of the downloaded file (first 5 lines)

In [9]:

with open('data/wish.xye') as f:
    print(''.join(f.readlines()[:5]))

with open('data/wish.xye') as f: print(''.join(f.readlines()[:5]))

     9001.0830          616.5238        124.5646
     9006.8848          578.7690        123.1410
     9012.6904          574.1842        120.5078
     9018.5000          507.7390        111.3004
     9024.3125          404.6729        101.6163

Load experimentally measured data from downloaded file in XYE format

In [10]:

job.add_experiment_from_file('data/wish.xye')

job.add_experiment_from_file('data/wish.xye')

Display the experimentally measured data

In [11]:

job.show_experiment_chart()

job.show_experiment_chart()