[Pw_forum] Input for Quantum Espresso

[Ari P Seitsonen]

Dear Mohan maruthi sena,

   I do not have an opportunity to look at your .cif-file in detail just 
now, and you do not provide the full input file, so I can just guess with 
two errors that I am particularly good at doing myself:

  - Are your atomic coordinates in the crystal coordinates? Does your input 
file have the correct option for that?

  - Maybe your .cif file contains fractional occupations and thus several 
configurations with different atomic positions might be possible; I do not 
know what 'cif2qe.sh' would do in that case.

   Constructing the input file starting from a pdb file would probably not 
be too tedious (one might lose some symmetries, however, if present as the 
pdb uses few digits in the atomic positions, in Angstroms if I am not 
wrong). I do not fully understand your question 2), do you mean that the 
structure that you built from the .cif file is a slab structure? Or that 
the .cif contains a bulk structure and you want to create a slab starting 
from that input? Well, you have first to determine the direction along the 
surface of the slab and its normal (orthogonal to the surface), and then 
add 10 Angstroms or more in that direction (and naturally adjust the 
coordinates if they are in crystal coordiates).

   Hopefully this helps you at least a little bit forward.

     Greetings from Rome,

        apsi

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   Ari Paavo Seitsonen / Ari.P.Seitsonen at iki.fi / http://www.iki.fi/~apsi/
   Ecole Normale Supérieure (ENS), Département de Chimie, Paris
   Mobile (F) : +33 789 37 24 25    (CH) : +41 79 71 90 935


On Sun, 18 Jan 2015, Mohan maruthi sena wrote:

> Hi  all,
>             I recently started using espresso. I want to  optimize a crystal structure. By looking at the previous posts , I tried to
> use cif2qe.sh script to convert from .cif to .inp file.  I tried with various examples and it was working. I  could not prepare inp
> file for the attached cif file. I have visualized the cif file in vesta, gaussian and then saved those .cif file. It prepared input
> files but the atoms are too close.
> 
> 1) Can some please let me how to give prepare input file for espresso 5.1.1, using cif or pdb file?
> 
> 2) If want to create a slab structure and maintain 10 angstorms distance between the slabs? How can i do this in espresso?
> 
> 3) I have used the following server (http://j-ice.sourceforge.net/ondemand/index.html) but could not get the input file.
> 
> Please find the attached  cif and espresso input files.
> 
>