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[Chol-Jun Yu <yucj@ghi.rwth-aachen.de>]

I have attached some related data which include the strained unit cells 
and reference how to calculate the elastic constants.

Hope helpful.
Chol-Jun

Stephen.Hocker@mpa.uni-stuttgart.de wrote:
> Dear Abinit users,
>
> I'm trying to calculate the elastic constants of B2 NiAl using the serial
> version of Abinit 5.4.4, unfortunately I didn't obtain any results yet. Some
> values for the parameters in my infile must be wrong, but I have no idea
> which ones I should change.
> The calculation starting from an input file like the one for Al which is 
> given in the elastic tutorial stopped with the message:
> kpgsph : BUG -
>   The variables ikg, mkmem, and mpw  must satisfy ikg<=(mkmem-1)*mpw,
>   while the arguments of the routine are
>   ikg =    3060, mkmem =      20, mpw =     159
>   Probable cause: Known error in invars1 for parallel spin-polarized case.
>   Temporary solution: Change the number of parallel processes.
>   Action : contact ABINIT group.
>
> Therefore I decided to determine the elastic constants by calculation of the
> energies of strained samples. In these calculations the total energy should 
> increase parabolically with increasing strain. But it doesn't. Depending on 
> the parameters it usually increases somehow, but the curve is never a 
> parabola. In some cases it even decreases a little.  
> These are the parameters I already tried:
> ecut (280...480 eV)
> ngkpt (2 2 2...10 10 10)
> nband/fband 65/0.0d0 
> occopt 3...4
> tsmear 0.03...0.07
> I tried with different pseudopotentials (Troullier-Martins) as well, namely
> 13al.pspnc, 28ni.pspnc / 13-Al.LDA.fhi, 28-Ni.LDA.fhi,  13-Al.GGA.fhi,
> 28-Ni.GGA.fhi.
>
> What else could be wrong? Thanks for any help.
> Best regards,
> Stephen
>
> This is one of my infiles: 
> acell 5.7970482729504687 5.767560060000 5.767560060000 angstrom
> ecut 480 eV
> ionmov 0 
> ixc 1 
> kptopt 1 
> natom 16
> ngkpt 10 10 10 
> nstep 15 
> ntypat 2 
> nband 65
> occopt 4 
> tsmear 0.03
> toldfe 0.005 eV
> chkprim 0
> znucl 13 28
> typat 
> 1
> 1
> 1
> 1
> 1
> 1
> 1
> 1
> 2
> 2
> 2
> 2
> 2
> 2
> 2
> 2
> xangst 0.000000 0.000000 0.000000
> 0.000000 0.000000 2.883780
> 0.000000 2.883780 0.000000
> 0.000000 2.883780 2.883780
> 2.898524 0.000000 0.000000
> 2.898524 0.000000 2.883780
> 2.898524 2.883780 0.000000
> 2.898524 2.883780 2.883780
> 1.449262 1.441890 1.441890
> 1.449262 1.441890 4.325670
> 1.449262 4.325670 1.441890
> 1.449262 4.325670 4.325670
> 4.347786 1.441890 1.441890
> 4.347786 1.441890 4.325670
> 4.347786 4.325670 1.441890
> 4.347786 4.325670 4.325670


--
Chol-Jun Yu
Computational Materials Engineering (CME)
Institute of Minerals Engineering (GHI)
Center for Computational Engineering Science (CCES)
RWTH Aachen University (RWTH)
Jülich-Aachen Research Alliance (JARA)
Mauerstr. 5, D-52056 Aachen
Tel.: +49-241-8094989 Fax: +49-241-80695097

Attachment: First principles calculations of elastic properties of metals.pdf
Description: Adobe PDF document

   ndtset  11
   rprim1  1.0 -0.010 0.0 -0.010 1.0 0.0 0.0 0.0 1.000100010001
   rprim2  1.0 -0.008 0.0 -0.008 1.0 0.0 0.0 0.0 1.000064004096262
   rprim3  1.0 -0.006 0.0 -0.006 1.0 0.0 0.0 0.0 1.000036001296047
   rprim4  1.0 -0.004 0.0 -0.004 1.0 0.0 0.0 0.0 1.000016000256004
   rprim5  1.0 -0.002 0.0 -0.002 1.0 0.0 0.0 0.0 1.000004000016
   rprim6  1.0  0.000 0.0  0.000 1.0 0.0 0.0 0.0 1.0
   rprim7  1.0  0.002 0.0  0.002 1.0 0.0 0.0 0.0 1.000004000016
   rprim8  1.0  0.004 0.0  0.004 1.0 0.0 0.0 0.0 1.000016000256004
   rprim9  1.0  0.006 0.0  0.006 1.0 0.0 0.0 0.0 1.000036001296047
  rprim10  1.0  0.008 0.0  0.008 1.0 0.0 0.0 0.0 1.000064004096262
  rprim11  1.0  0.010 0.0  0.010 1.0 0.0 0.0 0.0 1.000100010001
    acell  3*5.3516199522

     ecut  54.0
   occopt  4
   tsmear  0.02

   toldfe  1.0d-10
   prtgeo  0
   prtden  0
   prteig  0
    prtwf  0

   kptopt  1
    ngkpt  8  8  8
  nshiftk  1
   shiftk  0.0 0.0 0.0

    nstep  30
      ixc  7

   ntypat  2
    znucl  13 28
    natom  2
    typat  1 2
     xred  
           0.0   0.0   0.0
           0.5   0.5   0.5

   ndtset  11
   rprim1  0.980 0.0 0.0 0.0 1.020 0.0 0.0 0.0 1.000400160064026
   rprim2  0.984 0.0 0.0 0.0 1.016 0.0 0.0 0.0 1.000256065552782
   rprim3  0.988 0.0 0.0 0.0 1.012 0.0 0.0 0.0 1.000144020738986
   rprim4  0.992 0.0 0.0 0.0 1.008 0.0 0.0 0.0 1.000064004096262
   rprim5  0.996 0.0 0.0 0.0 1.004 0.0 0.0 0.0 1.000016000256004
   rprim6  1.000 0.0 0.0 0.0 1.000 0.0 0.0 0.0 1.0
   rprim7  1.004 0.0 0.0 0.0 0.996 0.0 0.0 0.0 1.000016000256004
   rprim8  1.008 0.0 0.0 0.0 0.992 0.0 0.0 0.0 1.000064004096262
   rprim9  1.012 0.0 0.0 0.0 0.988 0.0 0.0 0.0 1.000144020738986
  rprim10  1.016 0.0 0.0 0.0 0.984 0.0 0.0 0.0 1.000256065552782
  rprim11  1.020 0.0 0.0 0.0 0.980 0.0 0.0 0.0 1.000400160064026
    acell  3*5.3516199522

     ecut  54.0
   occopt  4
   tsmear  0.02

   toldfe  1.0d-10
   prtgeo  0
   prtden  0
   prteig  0
    prtwf  0

   kptopt  1
    ngkpt  8  8  8
  nshiftk  1
   shiftk  0.0 0.0 0.0

    nstep  30
      ixc  7

   ntypat  2
    znucl  13 28
    natom  2
    typat  1 2
     xred  
           0.0   0.0   0.0
           0.5   0.5   0.5