Banduppy for non-orthogonal system

[SamforD95]

To whom it may concern

Firstly, thank you for this designed routin in retail.
I am trying to use the program in QE for an hexagonal lattice system,
which features fractional coefficient in the supercell section.

The program complains directly, as follow:

unfolding_path.py", line 129, in init
super(UnfoldingPath,self).init(supercell,kpointsPBZ)

unfolding_path.py", line 23, in init
assert np.linalg.norm(np.array(supercell)-supercell_int)<1e-14 ,
AssertionError: supercell should consist of integers, found [[1, 0, 0], [-0.5, 0.8660254037844386, 0], [0, 0, 1.22924106]]

Have I plugged in smth wrong or is there a work around for this?
Thank you in advance
Samuele

[stepan-tsirkin]

Hi @SamforD95

The supercell should be composed of an integer number of primitive cells, i.e the lattice vectors of the supercell should be expressed in the basis of the primitive cell with integer coefficients. This is a fundamental condition for unfolding to be mathematically defined.

Those coefficients are those that should be introduced as a supercell parameter of UnfoldingPath .