Constructing cell from parameters

[t-reents]

Dear all,

I think I found a small typo/error in the methods related to the ibrav parameters.

In the PW Input documentation one finds that the first lattice vector of the reconstructed cell for an orthorhombic base-centered structure (ibrav=-9) has the following shape:

v1 = (a/2, -b/2, 0)

Therefore, I think the following code needs to be adapted so that the minus is in the second component of the first lattice vector and not in the second lattice vector.

qe-tools/qe_tools/parsers/_input_base.py

Lines 984 to 988 in 5fe555c

	elif ibrav == -9:
	# -9 as 9, alternate description
	# v1 = (a/2,-b/2,0), v2 = (a/2,-b/2,0), v3 = (0,0,c)
	cell = np.array([[0.5 * alat, 0.5 * b, 0.], [0.5 * alat, -0.5 * b, 0.],
	[0., 0., c]])