This notebook shows some examples of methods on a BandStructureSymmLine object (gettting band gaps, vbm, etc...) and basic plotting. Written by Geoffroy Hautier (geoffroy.hautier@uclouvain.be)

We start by querying the MP database for a band structure object. Please note that you could get such an object from a run (VASP, ABINIT, ...) using the methods in pymatgen.io

from pymatgen.matproj.rest import MPRester
from pymatgen.electronic_structure.core import Spin
#This initiliazes the Rest connection to the Materials Project db. Put your own API key.
a=MPRester("YOUR_API_KEY")
#load the band structure from mp-3748, CuAlO2 from the MP db
bs=a.get_bandstructure_by_material_id("mp-3748")

We print some information about the band structure

#is the material a metal (i.e., the fermi level cross a band)
print bs.is_metal()
#print information on the band gap
print bs.get_band_gap()
#print the energy of the 20th band and 10th kpoint
print bs.bands[Spin.up][20][10]
#print energy of direct band gap
print bs.get_direct_band_gap()
#print information on the vbm
print bs.get_vbm()

False
{'energy': 1.7978000000000005, 'transition': u'(0.591,0.409,0.000)-\\Gamma', 'direct': False}
18.0201
2.6904
{u'kpoint': <pymatgen.electronic_structure.bandstructure.Kpoint object at 0x5192610>, u'kpoint_index': [123], u'energy': 6.1023, u'band_index': {1: [15]}, u'projections': {}}

Here, we plot the bs object. By default for an insulator we have en energy limit of cbm+4eV and vbm-4 eV

%matplotlib inline
from pymatgen.electronic_structure.plotter import BSPlotter
plotter=BSPlotter(bs)
plotter.get_plot().show()

We plot the Brillouin zone with the path which was used for the band structure

plotter.plot_brillouin()