Introduction

This notebook shows how to plot an XRD plot for the two polymorphs of CsCl ($Pm\overline{3}m$ and $Fm\overline{3}m$). You can also use matgenie.py's diffraction command to plot an XRD pattern from a structure file.

# Uncomment the subsequent lines in this cell to install dependencies for Google Colab.
# !pip install pymatgen==2022.2.27

# Set up some imports that we will need
from IPython.display import Image, display
from pymatgen.analysis.diffraction.xrd import XRDCalculator
from pymatgen.core import Lattice, Structure

%matplotlib inline

$\alpha$-CsCl ($Pm\overline{3}m$)

Let's start with the typical $\alpha$ form of CsCl.

# Create CsCl structure
a = 4.209  # Angstrom
latt = Lattice.cubic(a)
structure = Structure(latt, ["Cs", "Cl"], [[0, 0, 0], [0.5, 0.5, 0.5]])

c = XRDCalculator()
c.show_plot(structure)

Compare it with the experimental XRD pattern below.

display(Image(filename=("./PDF - alpha CsCl.png")))

$\beta$-CsCl ($Fm\overline{3}m$)

Let's now look at the $\beta$ (high-temperature) form of CsCl.

# Create CsCl structure
a = 6.923  # Angstrom
latt = Lattice.cubic(a)
structure = Structure(
    latt,
    ["Cs", "Cs", "Cs", "Cs", "Cl", "Cl", "Cl", "Cl"],
    [
        [0, 0, 0],
        [0.5, 0.5, 0],
        [0, 0.5, 0.5],
        [0.5, 0, 0.5],
        [0.5, 0.5, 0.5],
        [0, 0, 0.5],
        [0, 0.5, 0],
        [0.5, 0, 0],
    ],
)

c.show_plot(structure)

Compare it with the experimental XRD pattern below.

display(Image(filename=("./PDF - beta CsCl.png")))