[Wien] Suggestions on the Hellmann-Feynman Force File : analyse_phonon_lapw

[Ghosh SUDDHASATTWA]

Dear Wien2k users, 

I have carried out the phonon calculations on AB2 system and after
analyse_phonon_lapw, I get the following 

Sum of forces (should be zero) for case   1:    0.1140    0.0000    0.0000

Sum of forces (should be zero) for case   2:   -0.1000    0.0000   -0.0160

Sum of forces (should be zero) for case   3:    0.0010    0.0390   -0.0030

Sum of forces (should be zero) for case   4:    0.0010   -0.0270   -0.0080

Sum of forces (should be zero) for case   5:    0.0060    0.0000    0.0810

Sum of forces (should be zero) for case   6:    0.0120    0.0000   -0.1070

Sum of forces (should be zero) for case   7:   -0.0120    0.0000    0.0070

Sum of forces (should be zero) for case   8:    0.0140    0.0000   -0.0060

Sum of forces (should be zero) for case   9:    0.0040   -0.0160    0.0050

Sum of forces (should be zero) for case  10:    0.0090   -0.0060   -0.0100

Sum of forces (should be zero) for case  11:    0.0100    0.0000    0.0260

Sum of forces (should be zero) for case  12:    0.0060    0.0000   -0.0230

Sum of forces (should be zero) for case  13:   -0.1000    0.0000    0.0010

Sum of forces (should be zero) for case  14:    0.1050    0.0000    0.0110

Sum of forces (should be zero) for case  15:    0.0060   -0.0180    0.0100

Sum of forces (should be zero) for case  16:   -0.0010    0.0310   -0.0070

Sum of forces (should be zero) for case  17:    0.0020    0.0000   -0.1310

Sum of forces (should be zero) for case  18:   -0.0060    0.0000    0.1320

Sum of forces of all displacements:    0.5090    0.1370    0.5840

displacements           1  and           2  can be symmetrized

 The following forces differ by more than 20 %:

 atom   3     0.093     0.000     2.645

        3    -0.094     0.000     2.193

 displacements           3  and           4  can be symmetrized

 The following forces differ by more than 20 %:

 displacements           5  and           6  can be symmetrized

 The following forces differ by more than 20 %:

 atom   2    -0.012     0.000    -9.745

        2    -0.014     0.000     5.051

 atom   3     0.231     0.000     3.018

        3    -0.195     0.000     1.870

 atom   4    -0.206     0.000     3.023

        4     0.224     0.000     1.867

 displacements           7  and           8  can be symmetrized

 The following forces differ by more than 20 %:

 atom   3     1.531     0.000     3.489

        3    -1.356     0.000     1.401

 displacements           9  and          10  can be symmetrized

 The following forces differ by more than 20 %:

 displacements          11  and          12  can be symmetrized

 The following forces differ by more than 20 %:

 atom   3     1.005     0.000     3.046

        3    -0.942     0.000     1.807

 atom   4    -0.974     0.000     3.041

        4     0.964     0.000     1.799

 displacements          13  and          14  can be symmetrized

 The following forces differ by more than 20 %:

 atom   1     1.719     0.000    -3.421

        1    -1.894     0.000    -1.350

 atom  12     0.719     0.000    31.755

       12    -0.516     0.000    31.834

 displacements          15  and          16  can be symmetrized

 The following forces differ by more than 20 %:

 displacements          17  and          18  can be symmetrized

 The following forces differ by more than 20 %:

 atom   4     0.018     0.000     4.296

        4     0.013     0.000     0.301

 atom  10     0.000     0.000   -37.751

       10     0.000     0.000   -25.822

Sum of forces of all symm.displ:       0.0000    0.0000    0.0000

 

 

 

I need the suggestion on if the forces are ok ????

( The command in run_phonon was run_lapw -I -i 200 -cc 0.0001 -in1ef -p -fc
0.1) 

 

Or it requires still more accurate forces (with fc 0.01 or lesser) 

 

Thanks 

Suddhasattwa 

 

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