[Pw_forum] Question on environ

[veronica sanchez]

Dear all,

I am a young researcher working on adsorption of organic molecules upon
carbonate surface. I would like to evaluate the solvation effect on it, so,
in order to do that I would like to employ the SCCS recently implemented on
the QE.

As far as I understand to add the solvent environment to the system
composed by the organic molecule adsorbed upon the surface, I have to set
up the environ.in as:

 &ENVIRON
   !
   verbose = 0
   environ_thr = 10 (system is big, an orthorhombic dimension, which
largest size is aroung 60 angstroms )
   environ_type = 'input'
   eps_mode = 'full'
   tolrhopol = 1.D-11
   mixrhopol = 0.6
   env_static_permittivity = 1 (79 for water)
   env_surface_tension = 0    (50 for water)
   !
/

And we add the line:
isolated_system='slabz'
to the &SYSTEM section of the QE input file.

Did I understand correctly? the environ.in is ok?

If so, I would like to follow with the next question.

As I was mention on the begging, I would like to calculate the adsorption
energy of this molecule in the solvent environment, therefore I have to
calculate two more systems: the surface and the molecule. For the surface I
understand that the same conditions have to be applied (the same environ.in
and the same 'isolated_system' in the QE file). Now, for the isolated
molecule I understand we could use the same environ.in (just changing the
 environ_thr to 0.1 as was indicating for molecules), but to maintain the
same cell dimensions as for the surface case, it is correct to use
'isolated_system'='slabz' in this case? Because 'pcc' only applies for
cubic systems, right?

I hope my questions were exposed in an understandable way and I apologize
if my English is not fully correct.

I would be grateful for any suggestion on how to proceed with this
calculation.

Thanks,

Regards

-- 
Dra. Verónica M. Sánchez
CSC-CONICET
Godoy Cruz 2390
1425 Ciudad de Buenos Aires
Argentina
Tel 54 11 4899 5500 ext 5616
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