Page 1 of 1

PRICELV / incommensurate direct and primitive lattices

Posted: Thu Feb 01, 2024 12:30 am
by 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.

Code: Select all

 ----------------------------------------------------------------------------
|                                                                             |
|     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!!! <----       |
|                                                                             |
 -----------------------------------------------------------------------------
 

Re: PRICELV / incommensurate direct and primitive lattices

Posted: Thu Feb 01, 2024 10:16 am
by 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:

Code: Select all

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.

Re: PRICELV / incommensurate direct and primitive lattices

Posted: Thu Feb 01, 2024 6:51 pm
by 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