return mu
def _get_number_of_electrons(energies, weights, chemical_potential,
temperature):
T = temperature
g = 3 - len(energies)
mu = chemical_potential
n = 0
for energies_spin in energies:
for E, w in zip(np.array(energies_spin), weights):
n += np.sum(1.0 / (1 + np.exp((E - mu) / T))) * w
return n * g
if __name__ == '__main__':
from cogue.interface.vasp_io import Vasprunxml
import sys
T = 0.4
print "Temperature %f K (%f eV)" % (T / Kb, T)
vasprun = Vasprunxml(sys.argv[1])
succeeded = vasprun.parse_eigenvalues()
eigvals = vasprun.get_eigenvalues()
kpoints, weights = vasprun.get_kpoints()
mu = get_chemical_potential(eigvals, weights, T, 16)
print "Chemical potential:", mu
print "Entropy (T*S):", get_entropy(eigvals, weights, mu, T) * T
