The ABINIT Users Mailing List ( CLOSED )

[digest <trp6@case.edu>]

Dear Users/ Developer. 

I am interested to calculate the phonon structure of LuN.  Please see the 
input
file below. Where I qpt  used were generated by running one iteration
calculation with kptopt 1, nshftk=1, shftk=0 0 0. After this I merged the ddb
database using mrgddb utility. 

While trying to analyze IFC, waht's the procedure to choose the nqshft and
q1shft. I tried as specified in tutorial, 1 and 3*0 but the run fails with the
following message.

   The dynamical matrix number     3 cannot be built,
  since no blok with wavevector    0.000000E+00    3.333333E-01    
3.333333E-01
  has been found.

If I choose the following like nqshft 4 and q1shft  0.5 0.5 0.5 , 0.0 0.0 0.5 
,
0.0 0.5 0.0 , 0.5 0.0 0.0the run stops with following error 

The dynamical matrix number     2 cannot be built,
 since no blok with wavevector    0.000000E+00    8.333333E-02    8.333333E-02
 has been found.

So how do I determine the correct nqshfit and nq1shft  so that it uses the 
grid
used to generate the ddb and does not give me error message. 

Or is there anyway to specify kptgrid by hand so that I don't run that 
problem.


Your any help would be greatly appreciated. 

Thanks. 

Tula 


Following is my input file. # Crystalline Scn  : computation of the phonqsnon
spectrum
                                                                              
 
                                                                        
   ndtset   16
#Set 1 : ground state self-consistency
                                                                              
 
                                                                        
  getwfk1   0            # Cancel default
  kptopt1   1            # Automatic generation of k points, taking
                         # into account the symmetry
    nqpt1   0            # Cancel default
  tolvrs1   1.0d-22      # SCF stopping criterion (modify default)
  rfphon1   0            # Cancel default
                                                                              
 
                                                                        
#Q vectors for all datasets
                                                                              
 
                                                                        
#Complete set of symmetry-inequivalent qpt chosen to be commensurate
# with kpt mesh so that only one set of GS wave functions is needed.
#Generated automatically by running GS calculation with kptopt=1,
# nshift=0, shiftk=0 0 0 (to include gamma) and taking output kpt set
# file as qpt set. Set nstep=1 so only one iteration runs.
                                                                              
 
                                                                        
     nqpt   1            # One qpt for each dataset (only 0 or 1 allowed)
                         # This is the default for all datasets and must
                         #  be explicitly turned off for dataset 1.
                                                                              
 
                                                                              
 
             
     qpt2   0.00000000E+00  0.00000000E+00  0.00000000E+00
     qpt3   0.00000000E+00  0.00000000E+00  0.00000000E+00
     qpt4   1.66666667E-01  0.00000000E+00  0.00000000E+00
     qpt5   3.33333333E-01  0.00000000E+00  0.00000000E+00
     qpt6   5.00000000E-01  0.00000000E+00  0.00000000E+00
     qpt7   1.66666667E-01  1.66666667E-01  0.00000000E+00
     qpt8   3.33333333E-01  1.66666667E-01  0.00000000E+00
     qpt9   5.00000000E-01  1.66666667E-01  0.00000000E+00
     qpt10 -3.33333333E-01  1.66666667E-01  0.00000000E+00
     qpt11 -1.66666667E-01  1.66666667E-01  0.00000000E+00
     qpt12  3.33333333E-01  3.33333333E-01  0.00000000E+00
     qpt13  5.00000000E-01  3.33333333E-01  0.00000000E+00
     qpt14 -3.33333333E-01  3.33333333E-01  0.00000000E+00
     qpt15  5.00000000E-01  5.00000000E-01  0.00000000E+00
     qpt16  5.00000000E-01  3.33333333E-01  1.66666667E-01
     qpt17 -3.33333333E-01  3.33333333E-01  1.66666667E-01
     qpt18 -3.33333333E-01  5.00000000E-01  1.66666667E-01
                                                                              
 
                                                                        
#Set 2 : Response function calculation of d/dk wave function
                                                                              
 
                                                                        
    iscf2   -3         # Need this non-self-consistent option for d/dk
  kptopt2   2          # Modify default to use time-reversal symmetry
  rfphon2   0          # Cancel defaulttolvrs2   0.0        # Cancel default
for d/dk
  tolwfr2   1.0d-22    # Use wave function residual criterion instead
                                                                              
 
                                                                        
#Set 3 : Response function calculation of Q=0 phonons and electric field pert.
                                                                              
 
                                                                        
  getddk3   2          # d/dk wave functions from last dataset
  kptopt3   2          # Modify default to use time-reversal symmetry
  rfelfd3   3          # Electric-field perturbation response only
                                                                              
 
                                                                        
#Sets 4-10 : Finite-wave-vector phonon calculations (defaults for all 
datasets)
                                                                              
 
                                                                        
   getwfk   1          # Use GS wave functions from dataset1
   kptopt   3          # Need full k-point set for finite-Q response
   rfphon   1          # Do phonon response
  rfatpol   1 2        # Treat displacements of all atoms
    rfdir   1 1 1      # Do all directions (symmetry will be used)
   tolvrs   1.0d-8     # This default is active for sets 3-10
                                                                              
 
                                                                        
                                                                              
 
                                                                        
#######################################################################
                                                                              
 
                                                                        
#Definition of the unit cell
    acell   8.995098918  8.995098918  8.995098918
    rprim   0.0  0.5  0.5   # In lessons 1 and 2, these primitive vectors
            0.5  0.0  0.5   # (to be scaled by acell) were 1 0 0  0 1 0  0 0 1
            0.5  0.5  0.0   # that is, the default.
                                                                              
 
                                                                        
#Definition of the atom types
   ntypat   2         # There are two types of atom
    znucl   71 7    # The keyword "znucl" refers to the atomic number of the
                      # possible type(s) of atom. The pseudopotential(s)
                      # mentioned in the "files" file must correspond
                      # to the type(s) of atom. Here, type 1 is the Aluminum,
                      # type 2 is the Arsenic.
                                                                              
 
                                                                        
#Definition of the atoms
    natom   2         # There are two atoms
    typat   1 2       # The first is of type 1 (Al), the second is of type 2
(As).     xred   0.0  0.0  0.0
            0.5 0.5 0.5
                                                                              
 
                                                                        
#Gives the number of band, explicitely (do not take the default)
    nband   11
                                                                              
 
                                                                        
#Exchange-correlation functional
                                                                              
 
                                                                        
      ixc   7            # LDA fhi pseudopotential
                                                                              
 
                                                                        
#Definition of the planewave basis set
                                                                              
 
                                                                        
     ecut   35.0           # Maximal kinetic energy cut-off, in Hartree
                                                                              
 
                                                                        
#Definition of the k-point grid
   ngkpt    6 6 6
   nshiftk     4
   shiftk      0.5 0.5 0.5
               0.5 0.0 0.0
               0.0 0.5 0.0
               0.0 0.0 0.5
                                                                              
 
                                                                        
#Definition of the SCF procedure
    nstep   100         # Maximal number of SCF cycles
    ntime   100