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--- exercises:common:bs [2022/09/08 15:28] – created jglan
+++ exercises:common:bs [2023/01/17 20:39] (current) – jglan
@@ Line 1: / Line 1: @@
-====== Getting the band structure of WO$_3$ Lattice ======
+====== Band structure of WO$_3$ Lattice ======
+In this exercise, we will carry out band structure calculation using K-point sampling for Cubic lattice WO$_3$. The reference DOS and band structure you can find in [[http://pubs.acs.org/doi/abs/10.1021/cm3032225|this paper]]
+{{:exercises:2017_uzh_cmest:wo3.jpeg?1200|}}
+<note important>K-point sampling only support GGA functionals.
+Band structure calculations using high-level electronic structure theory, such as hybrid functionals are not available in CP2K.
+</note>
 To get the band structure for <chem>WO3</chem>, only a few changes are required compared to the previous example for [[PDOS|calculating the PDOS]]:
@@ Line 13: / Line 22: @@
    METHOD Quickstep
    &DFT
+      UKS
       BASIS_SET_FILE_NAME  BASIS_MOLOPT
       POTENTIAL_FILE_NAME  POTENTIAL
@@ Line 172: / Line 182: @@
 gnuplot>plot for [i=4:23] "WO3.bs.set-1.csv" u 0:i w l t ""
  </code>
-<file python cp2k_bs2csv.py>
+<file python plt_band.py>
-#!/usr/bin/env python
+import numpy as np
-"""
+import matplotlib.pyplot as plt
-Convert the CP2K band structure output to CSV files
-"""
-import re
-import argparse
-SET_MATCH = re.compile(r'''
-[ ]*
-  SET: [ ]* (?P<setnr>\d+) [ ]*
-  TOTAL [ ] POINTS: [ ]* (?P<totalpoints>\d+) [ ]*
-  \n
-(?P<content>
-  [\s\S]*?(?=\n.*?[ ] SET|$)  # match everything until next 'SET' or EOL
-)
-''', re.VERBOSE)
-SPOINTS_MATCH = re.compile(r'''
-[ ]*
-  POINT [ ]+ (?P<pointnr>\d+) [ ]+ (?P<a>\S+) [ ]+ (?P<b>\S+) [ ]+ (?P<c>\S+)
-''', re.VERBOSE)
-POINTS_MATCH = re.compile(r'''
-[ ]*
-  Nr\. [ ]+ (?P<nr>\d+) [ ]+
-  Spin [ ]+ (?P<spin>\d+) [ ]+
-  K-Point [ ]+ (?P<a>\S+) [ ]+ (?P<b>\S+) [ ]+ (?P<c>\S+) [ ]*
-  \n
-[ ]* (?P<npoints>\d+) [ ]* \n
-(?P<values>
-  [\s\S]*?(?=\n.*?[ ] Nr|$)  # match everything until next 'Nr.' or EOL
-)
-''', re.VERBOSE)
-if __name__ == '__main__':
+file=np.genfromtxt('WO3.bs')
-    parser = argparse.ArgumentParser(description=__doc__)
-    parser.add_argument('bsfilename', metavar='bandstructure-file', type=str,
-                        help="the band structure file generated by CP2K")
-    args = parser.parse_args()
+bs = open ('WO3.bs','r')
+line = bs.readline().split()
+num_points, num_k_points, num_bands = int(line[3]),int(line[6]),int(line[8])
+sp=[""]*num_points
+i=0
+for i in range(num_points):
+    line = bs.readline().split()
+    sp[i] = line[7]
-    with open(args.bsfilename, 'r') as fhandle:
-        for kpoint_set in SET_MATCH.finditer(fhandle.read()):
-            filename = "{}.set-{}.csv".format(args.bsfilename,
-                                              kpoint_set.group('setnr'))
-            set_content = kpoint_set.group('content')
-            with open(filename, 'w') as csvout:
+new=np.resize(file,(num_k_points*2,num_bands,3))
-                print(("writing point set {}"
+ener=new[:,:,1:2]
-                       " (total number of k-points: {totalpoints})"
+ener=np.resize(new[:,:,1:2],(num_k_points*2,num_bands)).transpose()
-                       .format(filename, **kpoint_set.groupdict())))
+num_homo = len(new[:,:,2][1][new[:,:,2][1]==1])
+num_lumo = len(new[:,:,2][1][new[:,:,2][1]==0])
-                print("  with the following special points:")
+for i in range(num_homo):
-                for point in SPOINTS_MATCH.finditer(set_content):
+    plt.plot(ener[i,::2],color='k')
-                    print("  {pointnr}: {a}/{b}/{c}".format(
+for i in range(num_lumo):
-                        **point.groupdict()))
+    plt.plot(ener[i+num_homo,::2],color='k',linestyle='-')
-                for point in POINTS_MATCH.finditer(set_content):
+#plt.ylim([-4,6])
-                    results = point.groupdict()
+plt.xlim([0,num_k_points-1])
-                    results['values'] = " ".join(results['values'].split())
+plt.xticks(np.linspace(0,num_k_points-1,num_points),sp)
-                    csvout.write("{a} {b} {c} {values}\n".format(**results))
+plt.ylabel("Energy (eV)")
+plt.show()
 </file>