[Pw_forum] Body Centered Tetragonal

[vtmtrinh at caltech.edu]

Dear PWSCF,

I am working on a system, which has a unit cell of body centered
tetragonal.  The Cartesian coordinates that I have are generated from a
different set of primitive vectors:

p1=(a,0,0), p2=(0,a,0), and p3=(a/2, a/2, c/2

The primitive vectors for the same unit cell in INPUT_PW are different,
which are:

V1 = a/2(1,-1,c/a), V2=a/2(1,1,c/a), V3=a/2(-1,-1,c/a)

Therefore, I cannot use the current coordinates that I have for the input
to run pw.x.  If I would like to add this option or change the primitive
vectors in the code, could you show me which parts of the code that I
should look at to do this. (I did a quick search, I see some possible
files related to this, including PW/crystal_to_car.f90, and
Modules/cell_base.f90, but I could not get to the right parts that I
expect to see.  Since I do not have much time left, it would help me a lot
if you could help).

I appreciate in advance very much for your help,

Thank you,

Trinh Vo
JPL/CalTech