[Pw_forum] about kind of ibrav, cell parameters and thermo_pw.

[Mutlu COLAKOGULLARI]

Hello,

MAIN PROBLEM:
I want to use thermo_pw code but it does not allow to use of ibrav=0.

STORY:
The conventional cell of crystalline interested  is monoclinic type with 
Beta angle (ibrav=-12). In order to find primitive cell I used pymatgen 
code and then aconvasp-online. The final cell is MCLC5 type with cell 
parameters (W. Setyawan and S. Curtarolo's paper; 
http://arxiv.org/abs/1004.2974v1)  as following:

CELL_PARAMETERS angstrom
  5.38800000000   5.38950024192225    0.0000000000
-5.3880000000    5.38950024192225    0.0000000000
  0.0000000000    2.71796558242205   15.42537623828894

I have tested the MCLC5 cell type with xcrysden-kpath visualization. 
Everything is looking fine to me. In pw.x code I can use it safely with 
ibrav=0 but thermo_pw code.  The cell vectors are different from 
ibrav=12,-12,13. If I transform the Niggle form then I get the 
tricilinic type which is not proper for thermo_pw code, too. Here is the 
end of my knowledge.

QUESTION:
How can I transform the above cell parameters to the correct kind of 
ibrav type and celldm(1,...,6)?

with my best wishes,

      Mutlu.

-- 
PhD. Mutlu ÇOLAKOĞULLARI
Trakya Üniversitesi
Fen Fakültesi
Fizik Bölümü