[xcrysden] problems with visualisation of QE input file

[Tone Kokalj]

On Thu, 2014-01-16 at 13:09 +0100, Claudia Mangold wrote:
> Dear xcrysden developer(s),
> 
> I use xcrysden to visualise QE input and output and I mam very happy
> with it. Thanks a lot for providing this program for free to the
> community. So far I only discovered one problem of which I am not 100%
> sure if it is a bug or a misunderstanding from my side:

Actually it is the backward incompatibility (xcrysden does not yet
understand correctly the new QE's syntax of 

CELL_PARAMETERS bohr | angstroms

but implicitly assumes "alat" units for CELL_PARAMETERS.

> In QE input files you can specify
> 
> CELL_PARAMETERS and ATOMIC_POSITIONS in angstrom and in bohr. However,
> the visualisation with xcrysden works only properly with CELL_PARAMETERS
> specified in bohr.

As said above, it ignores both "bohr" and "angstrom", but when celldm(1)
or A (i.e. lattice parameter, aka "alat") is not specified, then it
assumes alat=1 bohr, which implies that CELL_PARAMETERS are actually in
bohr units.

This issue will be fixed in a new release.

Regards,
-- 
Anton Kokalj
J. Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia 
(tel: +386-1-477-3523 // fax:+386-1-477-3822)

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