[Pw_forum] ibrav=12

[Paolo Giannozzi]

On Feb 19, 2011, at 15:55 , Carlo Nervi wrote:

> I've been confused by the convenction used in quantum espresso.

the conventions used in QE for lattices are explained in detail in the
documentation. They may not be the smartest or the "more standard"
choice, though (not sure what is considered "standard" in  
crystallography).
Any proposal for improvement is welcome, as long as
- it is written in fortran and ready to be plugged into the code, and
- it is backward-compatible (does not affect existing input data).
An ugly but safe and straightforward way to achieve this is to define
more values of "ibrav". The relevant parts of code are the 30 lines or
so starting from
   IF ( celldm_(1) == 0.D0 .and. a /= 0.D0 ) THEN
in PW/input.f90, plus flib/latgen.f90

P.
---
Paolo Giannozzi, Dept of Chemistry&Physics&Environment,
Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222