Band gap

ase.dft.bandgap.bandgap(calc=None, direct=False, spin=<object object>, eigenvalues=None, efermi=None, output=None, kpts=None)

Calculates the band-gap.

Parameters:

calc: Calculator object

Electronic structure calculator object.

direct: bool

Calculate direct band-gap.

eigenvalues: ndarray of shape (nspin, nkpt, nband) or (nkpt, nband)

Eigenvalues.

efermi: float

Fermi level (defaults to 0.0).

Returns a (gap, p1, p2) tuple where p1 and p2 are tuples of indices of the valence and conduction points (s, k, n).

Example:

>>> gap, p1, p2 = bandgap(silicon.calc)
>>> print(gap, p1, p2)
1.2 (0, 0, 3), (0, 5, 4)
>>> gap, p1, p2 = bandgap(silicon.calc, direct=True)
>>> print(gap, p1, p2)
3.4 (0, 0, 3), (0, 0, 4)