[Pw_forum] Dispersion_correction parameter for Platinum

[Giuseppe Mattioli]

Dear Pallavi Bothra
look into the 5.0.2/Modules/mm_dispersion.f90 file: the Pt C_6 coefficient (2818.308; I do not remember the unit, but all coefficients are converted from 
the Grimme's paper cited in the file) is assigned there, but I suppose that its number of figures exceeds the corresponding field in the standard output 
of pw.x. So, do not worry! You are using the DFTD2 correction on Pt...:-) One last note: remember that the DFTD2 method overestimates the molecule-
surface interaction...
HTH

Giuseppe

On Monday 20 May 2013 10:58:54 Pallavi Bothra wrote:
> Dear all,
>              I want to study dispersion correction for Platium surface
> using espresso 5.0.2. My input file is as follows :
> /
>  &SYSTEM
>                        ibrav = 0,
>                    celldm(1) = 6.654
>                          nat = 41,
>                         ntyp = 4,
>                      ecutwfc = 40 ,
>                      ecutrho = 400 ,
>                  occupations = 'smearing' ,
>                      degauss = 0.01 ,
>                     smearing = 'marzari-vanderbilt' ,
>                        nspin = 2 ,
>     starting_magnetization(1) = 0.5 ,
>     starting_magnetization(2) = 0.5 ,
>                       london = .TRUE.
> 
> /
>  &ELECTRONS
>               electron_maxstep = 1000 ,
>                  conv_thr = 1.0d-8
>                  mixing_beta = 0.2 ,
>                mixing_mode = 'local-TF',
>                mixing_ndim = 10 ,
>             diagonalization = 'cg'
>  /
>  &IONS
>                upscale = 1000 ,
> 
>  /
> ATOMIC_SPECIES
>    Ni  58.6934    Ni.pbe-nd-rrkjus.UPF
>    Pt  195.084    Pt.pbe-nd-rrkjus.UPF
>    C   12.0107    C.pbe-rrkjus.UPF
>    H   1.00794    H.pbe-rrkjus.UPF
> ...............
> ................
> 
> But in output file while printing in C_6 value it is showing ********
> 
> That means dispersion correction has not been taken into account.
> 
> Can anyone please suggest me what should I do?
> 
> Thanks a lot
> 
> Regards
> Pallavi Bothra
> Graduate student
> JNCASR, Bangalore


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   Giuseppe Mattioli                            
   CNR - ISTITUTO DI STRUTTURA DELLA MATERIA   
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