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Given the following text description, write Python code to implement the functionality described below step by step
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Description:
 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
Step1:  We print some information about the band structure
Step2:  Here, we plot the bs object. By default for an insulator we have en energy limit of cbm+4eV and vbm-4 eV
Step3:  We plot the Brillouin zone with the path which was used for the band structure
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Python Code:
from pymatgen.ext.matproj import MPRester
from pymatgen.electronic_structure.core import Spin
#This initiliazes the Rest connection to the Materials Project db. Put your own API key if needed.
a = MPRester()
#load the band structure from mp-3748, CuAlO2 from the MP db
bs = a.get_bandstructure_by_material_id("mp-3748")
Explanation: 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
End of explanation
#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())
Explanation: We print some information about the band structure
End of explanation
%matplotlib inline
from pymatgen.electronic_structure.plotter import BSPlotter
plotter = BSPlotter(bs)
plotter.get_plot().show()
Explanation: Here, we plot the bs object. By default for an insulator we have en energy limit of cbm+4eV and vbm-4 eV
End of explanation
plotter.plot_brillouin()
Explanation: We plot the Brillouin zone with the path which was used for the band structure
End of explanation
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