[Pw_forum] init_london Error

[Giuseppe Mattioli]

Dear Vikas
You can also use the ab-initio implementation of vdW forces by switching on 
the input_dft="vdw-df" flag.
HTH
Giuseppe


On Tuesday 21 June 2011 16:40:02 Vikas Varshney wrote:
> Dear All,
>
> I am trying to relax my WS2 unit cell structure using vc-relax (using PBE
> pps) and I want to include disperson corrections to it. So, I tried using
> the london flag = .true. However, on starting my job I got an error
>
> 
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>%%% from  init_london  : error #         1
>      atom W   not found
> 
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>%%%
>
> After going through mm_dispersion.f90, I found that the vdw_radius and c_6
> parameters are given for first 54 atoms only (which corresponds to first 5
> periods of periodic table). Tungsten (W), with atomic number of 74 is in
> 6th period.
>
> I emailed Prof. Stefan Grimme (author of the references that are mentioned
> in mm_dispersion.f90) if anything was further pursued. He replied
> mentioning that they have approached this problem further and referred me
> to his website,
>
> http://toc.uni-muenster.de/DFTD3/
>
> and told me that this has already been implemented into major QM codes.
>
> Mentioning that, I have few questions.
> 1. I wanted to ask if QE has incorporated the additions DFT-D, recently.
> 2. Are there any other ways to incorporate dispersion interactions in
> calculations in DFT.
>
> Currently, I am running my simulations on 4.2 version of the code that I
> downloaded few months ago. I would high appreciate your insights in how
> should I go about solving this problem regarding dispersion interactions in
> Tungsten.
>
> Looking forward for a positive reply.
>
> Best Regards,
>
> Vikas Varshney,
> Computational Materials Scientist,
> Wright-Patterson Air Force Base, Dayton-OH (USA).



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   Giuseppe Mattioli                            
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