Simulation pd-xray NaCl¶

This example demonstrates how to simulate a powder diffraction pattern of NaCl for the X-ray case.

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='pd-xray')
print(job.type)

job = ed.Job(type='pd-xray') print(job.type)

Job type: pd-cwl-unp-1d-xray

Define a model¶

Create a phase object

In [4]:

phase = ed.Phase(name='nacl')

phase = ed.Phase(name='nacl')

Set space group

In [5]:

phase.space_group.name_hm_alt = 'F m -3 m'

phase.space_group.name_hm_alt = 'F m -3 m'

Set cell parameters

In [6]:

phase.cell.length_a = 5.691694

phase.cell.length_a = 5.691694

Add atoms

In [7]:

phase.atom_sites.append(label='Na',
                        type_symbol='Na',
                        fract_x=0,
                        fract_y=0,
                        fract_z=0,
                        occupancy=1,
                        u_iso_or_equiv=0.01)
phase.atom_sites.append(label='Cl',
                        type_symbol='Cl',
                        fract_x=0,
                        fract_y=0,
                        fract_z=0.5,
                        occupancy=1,
                        u_iso_or_equiv=0.01)

phase.atom_sites.append(label='Na', type_symbol='Na', fract_x=0, fract_y=0, fract_z=0, occupancy=1, u_iso_or_equiv=0.01) phase.atom_sites.append(label='Cl', type_symbol='Cl', fract_x=0, fract_y=0, fract_z=0.5, occupancy=1, u_iso_or_equiv=0.01)

Add phase to the job object

In [8]:

job.add_phase(phase=phase)
print(job.phases)

job.add_phase(phase=phase) print(job.phases)

Collection of 1 phases: ['nacl']

Show phase info in CIF format

In [9]:

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

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

data_nacl
_cell_length_a 5.691694
_cell_length_b 5.691694
_cell_length_c 5.691694
_cell_angle_alpha 90.00000000
_cell_angle_beta 90.00000000
_cell_angle_gamma 90.00000000
_space_group_name_H-M_ref 'F m -3 m'

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_U_iso_or_equiv
Na Na 0.00000000 0.00000000 0.00000000 1.00000000 Uiso 0.01
Cl Cl 0.00000000 0.00000000 0.5 1.00000000 Uiso 0.01

Display the crystal structure of a given model

In [10]:

job.show_crystal_structure(id='nacl')

job.show_crystal_structure(id='nacl')

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Define an experiment¶

Although in this example we only simulate the diffraction pattern, some parameters for the ‘virtual experiment’ still need to be set. For example, the wavelength of the X-ray beam, the range of 2-theta angles, etc.

Let's start by setting the range and step of the 2-theta angles. The other parameters will be set later.

In [11]:

job.instrument.twotheta_range_min = 20
job.instrument.twotheta_range_max = 160
job.instrument.twotheta_range_inc = 0.05

job.instrument.twotheta_range_min = 20 job.instrument.twotheta_range_max = 160 job.instrument.twotheta_range_inc = 0.05

Perform an analysis¶

Display the analysis chart before changing the values of other parameters from their default values.

In [12]:

job.show_simulation_chart()

job.show_simulation_chart()