[Wien] error in elastic constants

[prasad jayasena]

Dear wien2k community

I wanted to get the elastic constants of a cubic structure using elastic module in wien2k. I completed the calculation I am getting unacceptable values as below

 in GPa: 
c11=   -36037.828466 c12=    18133.340459 c44=       54.083125

I used the optimized correct structure file initially. However in the rhomb and tetra structures in the init_elast steps I had a warning " WARNING: Mult not equal. PLEASE CHECK outputnn-file". Since this warning I accepted the "NEW rhomb.struct_nn file" and "NEW tetra.struct_nn file". In those files the atomic positions are different from the initial correct structure file. 

The following is the atomic positions of case.struct 

14.730415 14.730415 14.730415 90.000000 90.000000 90.000000                   
ATOM   1: X=0.37500000 Y=0.87500000 Z=0.37500000
          MULT= 2          ISPLIT= 2
       1: X=0.62500000 Y=0.12500000 Z=0.62500000
U          NPT=  781  R0=0.00000500 RMT=    2.5000   Z: 92.000                 
LOCAL ROT MATRIX:    1.0000000 0.0000000 0.0000000
                     0.0000000 1.0000000 0.0000000
                     0.0000000 0.0000000 1.0000000
ATOM  -2: X=0.50000000 Y=0.50000000 Z=0.50000000
          MULT= 4          ISPLIT= 4
      -2: X=0.50000000 Y=0.75000000 Z=0.75000000
      -2: X=0.75000000 Y=0.75000000 Z=0.50000000
      -2: X=0.75000000 Y=0.50000000 Z=0.75000000
Al         NPT=  781  R0=0.00010000 RMT=    2.5000   Z: 13.000                 
LOCAL ROT MATRIX:    0.4082483-0.7071068 0.5773503
                     0.4082483 0.7071068 0.5773503
                    -0.8164966 0.0000000 0.5773503
  48      NUMBER OF SYMMETRY OPERATIONS



rhomb.struct

            RELA                                                              
 10.415976 10.415976 25.641396 90.000000 90.000000 90.000000                   
ATOM  -1: X=0.87500000 Y=0.87500000 Z=0.87500000
          MULT= 2          ISPLIT= 4
      -1: X=0.12500000 Y=0.12500000 Z=0.12500000
U 1        NPT=  781  R0=0.00000500 RMT=    2.5000   Z: 92.0                   
LOCAL ROT MATRIX:    1.0000000 0.0000000 0.0000000
                     0.0000000 1.0000000 0.0000000
                     0.0000000 0.0000000 1.0000000
ATOM  -2: X=0.50000000 Y=0.50000000 Z=0.50000000
          MULT= 1          ISPLIT= 4
Al2        NPT=  781  R0=0.00010000 RMT=    2.3900   Z: 13.0                   
LOCAL ROT MATRIX:    1.0000000 0.0000000 0.0000000
                     0.0000000 1.0000000 0.0000000
                     0.0000000 0.0000000 1.0000000
ATOM  -3: X=0.00000000 Y=0.50000000 Z=0.50000000
          MULT= 3          ISPLIT= 8
      -3: X=0.50000000 Y=0.50000000 Z=0.00000000
      -3: X=0.50000000 Y=0.00000000 Z=0.50000000
Al3        NPT=  781  R0=0.00010000 RMT=    2.3900   Z: 13.0                   
LOCAL ROT MATRIX:    0.0000000 0.5000000 0.8660254
                     0.0000000-0.8660254 0.5000000
                     1.0000000 0.0000000 0.0000000
  12      NUMBER OF SYMMETRY OPERATIONS

tetra.struct


10.398674 10.398674 14.779476 90.000000 90.000000 90.000000                   
ATOM  -1: X=0.00000000 Y=0.25000000 Z=0.87500000
          MULT= 2          ISPLIT=-2
      -1: X=0.00000000 Y=0.75000000 Z=0.12500000
U 1        NPT=  781  R0=0.00000500 RMT= 2.50000     Z: 92.0                   
LOCAL ROT MATRIX:    0.7071068-0.7071068 0.0000000
                     0.7071068 0.7071068 0.0000000
                     0.0000000 0.0000000 1.0000000
ATOM  -2: X=0.50000000 Y=0.50000000 Z=0.00000000
          MULT= 4          ISPLIT= 8
      -2: X=0.00000000 Y=0.50000000 Z=0.50000000
      -2: X=0.75000000 Y=0.25000000 Z=0.25000000
      -2: X=0.75000000 Y=0.75000000 Z=0.75000000
Al1        NPT=  781  R0=0.00010000 RMT= 2.38        Z: 13.0                   
LOCAL ROT MATRIX:    0.0000000 0.0000000 1.0000000
                     1.0000000 0.0000000 0.0000000
                     0.0000000 1.0000000 0.0000000


Can someone please tell me whether I should not accept these rhomb/tetra.struct file in the calculation? Is this the reason for wrong elastic constants?

However I couldn't find a way to continue without accepting the new structure for the. Otherwise errors continue in the init step and could not fin a way finish init . I tries both new and old schemes in the setrmt and I am working with wien2k 18.2 version

I appreciate your support.

Prasad