Uses pymatgen to produce a CRYSTAL bandstructure input file - deriving a continuous path from a CIF file.

bandstructure_path2crystal.py

#!/usr/bin/env python3

import sys
from pymatgen.core import Structure
from pymatgen.symmetry.bandstructure import HighSymmKpath
import networkx as nx


# ingore warnings
import warnings
warnings.filterwarnings("ignore")

# Check if input file is given
if len(sys.argv) != 2:
    print("Usage: " + sys.argv[0] + " <cif-inputfile>")
    sys.exit(1)

# Read input file
inputfile = sys.argv[1]

# Read structure from input file
struc = Structure.from_file(inputfile)

# Get high symmetry kpath
kplm = HighSymmKpath(struc)

# Get path
path_kpath = kplm.kpath['path']

# Get labels for path to feed into networkx
labels = []
for i, slist in enumerate(path_kpath):
    for j, element in enumerate(path_kpath[i]):
        if j == 0:
            labels.append(element)
        elif j == len(path_kpath[i]) - 1:
            labels.append(element)
        else:
            labels.append(element)
            labels.append(element)

# Create graph
G = nx.Graph()

# Add edges to graph
for i in range(int(len(labels) / 2)):
    G.add_edges_from([(labels[2 * i], labels[(2 * i) + 1])])

# Eulerize graph and get euler circuit
G_euler = nx.algorithms.euler.eulerize(G)
G_euler_circuit = nx.algorithms.euler.eulerian_circuit(G_euler)

# Convert euler circuit to list
G_euler_circuit = list(G_euler_circuit)
# length of euler circuit for output in CRYSTAL.D3 format
length = len(G_euler_circuit)

# Get new labels for kpoints
new_labels = []
for edge in G_euler_circuit:
    new_labels.append(edge[0])
new_labels.append(G_euler_circuit[-1][1])

k_vector = 12 # k-vector scaling factor

### OUPUT IN CRYSTAL.D3 FORMAT ###
print("BAND") # header
print(" - ".join(new_labels)) # labels
print(length, k_vector, 300, 1, 100, 1, 0)

kpoints = kplm.kpath['kpoints']
for edge in G_euler_circuit:
    # print kpoints formatted
    for kpoint in kpoints[edge[0]]:
        print(round(kpoint*k_vector), end=" ")
    print(end="")
    for kpoint in kpoints[edge[1]]:
        print(round(kpoint*k_vector), end=" ")
    print('G' if edge[0] == '\Gamma' else edge[0], end=" ")
    print('G' if edge[1] == '\Gamma' else edge[1])

print("END") # end of kpoints
print()