PRICELV / incommensurate direct and primitive lattices

[aaron_kaplan2]

Recently ran into this error message that I haven't seen elsewhere. I'm assuming the fix in this case is to adjust SYMPREC, but wanted to get confirmation from the devs and document in case others run into the same issue.

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|                                                                             |
|     EEEEEEE  RRRRRR   RRRRRR   OOOOOOO  RRRRRR      ###     ###     ###     |
|     E        R     R  R     R  O     O  R     R     ###     ###     ###     |
|     E        R     R  R     R  O     O  R     R     ###     ###     ###     |
|     EEEEE    RRRRRR   RRRRRR   O     O  RRRRRR       #       #       #      |
|     E        R   R    R   R    O     O  R   R                               |
|     E        R    R   R    R   O     O  R    R      ###     ###     ###     |
|     EEEEEEE  R     R  R     R  OOOOOOO  R     R     ###     ###     ###     |
|                                                                             |
|     PRICELV: current lattice and primitive lattice are incommensurate       |
|     within SYMPREC.                                                         |
|                                                                             |
|       ---->  I REFUSE TO CONTINUE WITH THIS SICK JOB ... BYE!!! <----       |
|                                                                             |
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[manuel_engel1]

Usually, this kind of error can appear when the parameters specified in the POSCAR file do not have enough precision or when there are small deviations in the atomic positions that can break the symmetries of the supercell by a small amount. Adjusting SYMPREC can fix the issue. In this case, please make sure that the symmetry/cell determination in VASP gives the expected results. The relevant information is found in the OUTCAR file around the following statement:

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Analysis of symmetry for initial positions (statically)

Maybe a more reliable approach would be to rebuild your supercell starting from one primitive cell. This guarantees high-precision atomic positions that more accurately obey the translational symmetries.

[aaron_kaplan2]

Thanks, Manuel!

With the default SYMPREC, VASP incorrectly identifies the space group as base-centered monoclinic, whereas spglib identifies it as body-centered cubic. Rerunning with SYMPREC = 1E-6 fixed both issues.

The POSCAR I used was already relaxed with VASP, and the symmetry-determination issues came up only on the final static calculation