[QE-users] not orthogonal operation in dos.x run only

[Lucas Dória]

Thanks for the answer,

So it is possible for a system to give satisfactory results in optimization calculations, and yet show symmetry problems in further routines? Also, my job using bands.x with the optimized structure for WS2 finished without getting symmetry issues, which does not occur for dos.x and projwfc.x calculations.

I will work on your tip and try to see if I can solve this problem by re-submitting relax calculations with better parameters, but it is yet strange to me why the 'not orthogonal operation' crash doesn't appear in vc-relax calc, neither in scf and nscf calculations, and we just take note of it in dos.x and projwfc.x routines.

With regards,

Lucas.

________________________________
De: users <users-bounces at lists.quantum-espresso.org> em nome de Paolo Giannozzi <p.giannozzi at gmail.com>
Enviado: sábado, 3 de outubro de 2020 13:06
Para: Quantum ESPRESSO users Forum <users at lists.quantum-espresso.org>
Assunto: Re: [QE-users] not orthogonal operation in dos.x run only

Obscure symmetry problems almost invariably come from the usage of "free" Bravais lattice (ibrav=0) and almost-symmetric-but-not-enough lattice vectors, or by almost-symmetric-but-not-enough atomic positions

Paolo

On Sat, Oct 3, 2020 at 6:36 PM Lucas Dória <lucasdoriacarvalho at hotmail.com<mailto:lucasdoriacarvalho at hotmail.com>> wrote:
Dear all,

I ran into this problem while doing a dos.x calculation (nscf and scf calculations finished succesfully):

'from checkallsym : error # 2
not orthogonal operation'

The structure is a WS2 bilayer. (WS2 is a layered material, we optimized bulk structure and then added vaccum in z-direction to get bilayer structure.)

When i looked up for possible reasons and solutions, I found this problem only occuring in vc-relax calculations. Our group did in fact optimized the hexagonal structure, but vc-relax calculations finished succesfully.

I add that we already studied electronic properties of another very similar hexagonal structure, of the same point group, namely MoS2, and we didn't get symmetry issues. (using v5.4 at the time)

So, I don't know why this problem of 'not orthogonal operation' is happening to WS2, and just in dos.x calculation, if it's a crash due to symmetry breaking. We think that the only major differences between WS2 and MoS2 are that W is heavier than Mo, and the PP used. But we are using an optimized ecutwfc.

Thanks in advance. QE-version used: 6.5.

Lucas.
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