BCT1

Body-centered tetragonal cell is defined by two parameters \(a\) and \(c\).

BCT lattice has variation BCT1 when \(c < a\).

Cell constructor

To get an example of the cell use wulfric.cell.SC_BCT().

wulfric.cell.sc_get_example() returns an example where \(a = 1.5\pi\) and \(c = \pi\).

import wulfric

cell = wulfric.cell.sc_get_example("BCT1")
atoms = dict(positions=[[0, 0, 0]], spglib_types=[1])

# To avoid multiple calls to spglib one can do it once and then pass spglib_data
# to the functions where it is needed
spglib_data = wulfric.get_spglib_data(cell=cell, atoms=atoms)

kp = wulfric.Kpoints.from_crystal(cell=cell, atoms=atoms, convention="SC")

conv_cell, conv_atoms = wulfric.crystal.get_conventional(
    cell=cell, atoms=atoms, convention="SC", spglib_data=spglib_data
)

prim_cell, prim_atoms = wulfric.crystal.get_primitive(
    cell=cell, atoms=atoms, convention="SC", spglib_data=spglib_data
)

variation = wulfric.crystal.sc_get_variation(
    cell=cell, atoms=atoms, spglib_data=spglib_data
)

assert variation == "BCT1"

print(variation)

BCT1

K-path

print(kp.path_string)

GAMMA-X-M-GAMMA-Z-P-N-Z1-M|X-P

High-symmetry points

print(kp.hs_table(decimals=4))

Name    rel_b1  rel_b2  rel_b3      k_x     k_y     k_z
GAMMA   0.0000  0.0000  0.0000   0.0000  0.0000  0.0000
M      -0.5000  0.5000  0.5000   1.3333  0.0000  0.0000
N       0.0000  0.5000  0.0000   0.6667  0.0000  1.0000
P       0.2500  0.2500  0.2500   0.6667  0.6667  1.0000
X       0.0000  0.0000  0.5000   0.6667  0.6667  0.0000
Z       0.3611  0.3611 -0.3611   0.0000  0.0000  1.4444
Z1     -0.3611  0.6389  0.3611   1.3333  0.0000  0.5556

Brillouin zone and default k-path

pe = wulfric.PlotlyEngine(_sphinx_gallery_fix=True)

pe.plot_brillouin_zone(
    cell=prim_cell, color="red", legend_label="Brillouin zone of the primitive cell"
)
pe.plot_brillouin_zone(
    cell=cell, color="chocolate", legend_label="Brillouin zone of the original cell"
)
pe.plot_kpath(kp=kp)
pe.plot_kpoints(kp=kp, only_from_kpath=True)

pe.show(axes_visible=False)

Cells of real space

pe = wulfric.PlotlyEngine(_sphinx_gallery_fix=True)

pe.plot_cell(cell=cell, legend_label="Original cell", color="Chocolate")
pe.plot_cell(cell=prim_cell, legend_label="Primitive cell", color="Black")
pe.plot_cell(cell=conv_cell, legend_label="Conventional cell", color="Blue")
pe.plot_wigner_seitz_cell(
    cell=prim_cell, legend_label="Wigner-Seitz cell", color="green"
)

pe.show(axes_visible=False)

Edge cases

If \(a = c\), then the lattice is CUB.