Hi folks,
I'm trying to setup first an SCF calculation and eventually a band structure
and relaxation calculation of a system with a NaCl-like lattice. Right now I
have an input file with 64 atoms in a cube shape, which corresponds to 8 unit
cells of the NaCl crystal structure. I've specified the CELL_PARAMETERS as well
as the atomic coordinates and chosen ibrav = 0. I'm getting the following
warning:
Message from routine setup:
using ibrav=0 with symmetry is DISCOURAGED, use correct ibrav instead
1. What is the correct solution for setting up my supercell; should I be
using ibrav = 1 instead and specifying the vectors for repeating my super cell?
2. For my own understanding, what is the issue with using symmetry with
ibrav=0? By symmetry am I correct to assume that this warning is referring to
symmetry detection within the supercell? If so, how does specifying ibrav=1
help with symmetry detection?
3. For what it's worth, it looks like symmetry detection is occurring at
some level since the code output "Found identity + ( 0.0000 0.2500 0.2500)
symmetry". However, I would expect to also see (0.25, 0, 0.25) and (0.25, 0,
0.25) as symmetry operations for an NaCl structure so perhaps there is a
problem here after all. Am I understanding correctly?
Best regards,
Ian Dunn (he/him)
ASML Wilton MDEV Analysis Architect
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