unit cell is not primitive  [SOLVED]

Total energy, geometry optimization, DFT+U, spin....

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Najmeh
Posts: 6
Joined: Mon May 14, 2018 3:20 pm

unit cell is not primitive  [SOLVED]

Post by Najmeh » Mon Oct 08, 2018 3:14 pm

Hi Dear
I am trying to optimize the lattice parameters for Lu2SiO5.
The input file is attached.
The error is:
chkprimit : ERROR -
According to the symmetry finder, the unit cell is
NOT primitive. The multiplicity is 2 .
The use of non-primitive unit cells is allowed
only when the input variable chkprim is 0.
Action : either change your unit cell (rprim or angdeg),
or set chkprim to 0.


Best.
Najmeh
Attachments
Lu2SiO5_Opt.in
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ebousquet
Posts: 469
Joined: Tue Apr 19, 2011 11:13 am
Location: University of Liege, Belgium

Re: unit cell is not primitive

Post by ebousquet » Tue Oct 09, 2018 5:36 pm

Dear Najmeh,
It means that the definition of your cell does not correspond to the unit cell (it is a multiple of it). You can keep running with this cell by adding the input flag chkprim 0 as specified in the message or you have to find the real unit cell of this crystal (the FINDYM software of the ISOTROPY suite can do that for example).
Best wishes,
Eric

Najmeh
Posts: 6
Joined: Mon May 14, 2018 3:20 pm

Re: unit cell is not primitive

Post by Najmeh » Tue Oct 16, 2018 10:43 pm

Thanks for your answer. my problem is solved.

best regards,
Najmeh

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