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[Michel Côté <michel.cote@umontreal.ca>]

Title: Re: [abinit-forum] phonon dispersion curves for MgH2

Hello,

Your system contains 6 atoms (natom=6). The variable rfatpol should be set to 1 to 6 if you want the full dynamical matrix.

Michel


Le 04/06/07 15:29, « asubedi@gmail.com » <asubedi@gmail.com> a écrit :

> Dear all,
>
> I followed the second tutorial on response function and using it I was also able to get the phonon dispersion curve for LiH. However, after that, I have been unsuccessfully trying to get the phonon dispersion curves for MgH2 for last few days. I seem to be able to get the dispersion curves only when I specify "ngqpt 2 2 2" in the analysis of DDB using anaddb, which results in a bit poor quality plot. As in the tutorial, the DDBs were creating using "ngkpt 4 4 4". However, specifying "ngqpt 4 4 4" to anaddb results in the following error:
>
>  symdm9 : ERROR -
>   Informations are missing in the DDB.
>   In blok     4 the following element is missing :
>   idir1,ipert1,idir2,ipert2=   1   3   1   3
>   Action : add the required information in the DDB,
>   or modify your input file.
>
> My *.in files are as follows:
>
> --- Start of file MgH2_test_1.in ----
> ndtset 20
>
>
> # Set 1 : ground state self-consistency
>
>    getwfk1         0
>    kptopt1         1
>
>    nqpt1           0
>    tolvrs1         1.0d-18
>    rfphon1         0
>
> # Q vectors for all datasets **the qpts were created as described in the tutorial. **
>         nqpt   1
>
>         qpt2        0.00000000E+00  0.00000000E+00  0.00000000E+00
>         qpt3        0.00000000E+00  0.00000000E+00  0.00000000E+00
>         qpt4        2.50000000E-01  0.00000000E+00  0.00000000E+00
>         qpt5        5.00000000E-01  0.00000000E+00  0.00000000E+00
>         qpt6        2.50000000E-01  2.50000000E-01  0.00000000E+00
>         qpt7        5.00000000E-01  2.50000000E-01  0.00000000E+00
>         qpt8        5.00000000E-01  5.00000000E-01  0.00000000E+00
>         qpt9        0.00000000E+00  0.00000000E+00  2.50000000E-01
>         qpt10       2.50000000E-01  0.00000000E+00  2.50000000E-01
>         qpt11       5.00000000E-01  0.00000000E+00  2.50000000E-01
>         qpt12       2.50000000E-01  2.50000000E-01  2.50000000E-01
>         qpt13       5.00000000E-01  2.50000000E-01  2.50000000E-01
>         qpt14       5.00000000E-01  5.00000000E-01  2.50000000E-01
>         qpt15       0.00000000E+00  0.00000000E+00  5.00000000E-01
>         qpt16       2.50000000E-01  0.00000000E+00  5.00000000E-01
>         qpt17       5.00000000E-01  0.00000000E+00  5.00000000E-01
>         qpt18       2.50000000E-01  2.50000000E-01  5.00000000E-01
>         qpt19       5.00000000E-01  2.50000000E-01  5.00000000E-01
>         qpt20       5.00000000E-01  5.00000000E-01  5.00000000E-01
>
> # Set 2 : Response function calculation of d/dk wave function
>
>     iscf2    -3
>   kptopt2    2
>   rfphon2    0
>   rfelfd2    2
>   tolvrs2    0.0
>   tolwfr2    1.0d-22
>
> # Set 3 : Response function calculation of Q=0 phonons and electric field
> #  pert.
>
>    getddk3  2
>    kptopt3  2
>    rfelfd3  3
>
> # Sets 4-10 : Finite-wave-vector phonon calculations
>
>    getwfk   1
>    kptopt   3
>    rfphon   1
>    rfatpol  1 2
>    rfdir    1 1 1
>    tolvrs   1.0d-8
>
>
> # Common input variables
>
>   acell 2*8.535514 5.707917
>   angdeg 90 90 90
>
>   spgroup 136
>   natom 6
>   ntypat 2
>   znucl 12 1
>
>   natrd  2
>   typat    1  2
>
>   xred
>      0.000 0.000 0.000
>      0.306 0.306 0.000
>
> # Gives the number of band
>   nband 4
>
> # Exchange-correlational functional
>   ixc 1
>
> # Definition of the planewave basis set
>   ecut 10.0
>
> # Definition of the k-point grid
>   ngkpt 4 4 4
>   nshftk 4
>   shiftk   0.0 0.0 0.5
>            0.0 0.5 0.0
>            0.5 0.0 0.0
>            0.5 0.5 0.5
>
> # Defintion of the SCF procedure
>   iscf   5
>   nstep  25
>   diemac 9.0
>
> ---- End of file MgH2_test_1.in ----
>
> ---- Start of file MgH2_test_3.in ----
> gH2_test_3.ddb.out
> MgH2 phonons on 4 4 4 mesh
> 18
> MgH2_test_1o_DS3_DDB
> MgH2_test_1o_DS4_DDB
> MgH2_test_1o_DS5_DDB
> MgH2_test_1o_DS6_DDB
> MgH2_test_1o_DS7_DDB
> MgH2_test_1o_DS8_DDB
> MgH2_test_1o_DS9_DDB
> MgH2_test_1o_DS10_DDB
> MgH2_test_1o_DS11_DDB
> MgH2_test_1o_DS12_DDB
> MgH2_test_1o_DS13_DDB
> MgH2_test_1o_DS14_DDB
> MgH2_test_1o_DS15_DDB
> MgH2_test_1o_DS16_DDB
> MgH2_test_1o_DS17_DDB
> MgH2_test_1o_DS18_DDB
> MgH2_test_1o_DS19_DDB
> MgH2_test_1o_DS20_DDB
>
> ---- End of file MgH2_test_3.in ----
>
> ---- Start of file MgH2_test_4.in ----
> Flags
>  ifcflag   1     ! Interatomic force constant flag
>
> !Wavevector grid number 1 (coarse grid, from DDB)
>   brav    1      ! Bravais Lattice : 1-S.C., 2-F.C., 3-B.C., 4-Hex.)
>   ngqpt   4  4  4   ! Monkhorst-Pack indices
>   nqshft  1         ! number of q-points in repeated basic q-cell
>   q1shft  3*0.0
>
> !Effective charges
>      asr   1     ! Acoustic Sum Rule. 1 => imposed asymetrically
>   chneut   1     ! Charge neutrality requirement for effective charges.
>
> !Interatomic force constant info
>   dipdip  1      ! Dipole-dipole interaction treatment
>   ifcana  1      ! Analysis of the IFCs
>   ifcout 10      ! Number of IFC's written in the output, per atom
>   natifc  1      ! Number of atoms in the cell for which ifc's are analysed
>    atifc  1      ! List of atoms
>
>   symdynmat 0
>
> ---- End of MgH2_test_4.in ----
>
> Since this process fails, I have not attached the remaining *.in files.
>
> Any help in identifying my error would be greatly appreciated. 


-- 
*************************************************************** 
  Michel Cote                          tel: +1 (514) 343-5628     
  Professeur agrégé                   fax: +1 (514) 343-2071               
  Département de physique 
  Université de Montréal 
  C.P. 6128, succ. Centre-ville 
  Montréal (Québec) H3C 3J7          Michel.Cote@umontreal.ca 
  Canada                   www.phys.umontreal.ca/~michel_cote 
***************************************************************