[Pw_forum] Choice of irreducible representations with ph.x

[Dal Corso Andrea]

You are using k=0 and q=0 so the phonon code uses the gamma_gamma
tricks. The problem is that the option nrapp with gamma_gamma tricks is
not supported. In the present version of ph.x there is no input variable
to disable the gamma gamma tricks when k=0 and q=0. I have added one
variable in the cvs version.
 
At the moment if you really need to use the nrapp option you can disable
the gamma gamma tricks adding the instruction
lgamma_gamma=.FALSE. 
after the lines:

  IF (nkstot==1.OR.(nkstot==2.AND.nspin==2)) THEN
     lgamma_gamma=(lgamma.AND.(ABS(xk(1,1))<1.D-12) &
                         .AND.(ABS(xk(2,1))<1.D-12) &
                         .AND.(ABS(xk(3,1))<1.D-12) )
  ENDIF

in PH/phq_readin.f90 and recompile.

However the option nrapp does not produce any frequency. You have to
write a small code to collect the pieces of the dynamical matrix that
you need and to diagonalize it.


Hope this helps,

Andrea

On Thu, 2009-04-02 at 18:55 +0200, Cristian Degli Esposti Boschi wrote:
> Here follows the input file for the preliminary scf calculation
> done using pw.x:
> 
> Thanks, Cristian
> 
> ---
> 
> &CONTROL
>    calculation  = "scf",
>    prefix       = "CoM",
>    pseudo_dir   = "/scratch/userinfm/cne0fm4a/pseudo/",
>    outdir       = "/scratch/userinfm/cne0fm4a/CoM/results/",
>    verbosity    = "high",
> /
> &SYSTEM
>    ibrav     = 0,
>    celldm(1) = 1.8897261D0,
>    nat       = 48,
>    ntyp      = 5,
>    ecutwfc   = 100.D0,
>    ecutrho   = 400.D0,
>    nbnd      = 100,
> /
> &ELECTRONS
>    electron_maxstep = 500,
>    conv_thr    = 1.D-6,
>    mixing_beta = 0.7D0,
>    diagonalization = "david",
> /
> CELL_PARAMETERS cubic
> 20.0  0.0  0.0
>   0.0 20.0  0.0
>   0.0  0.0  15.0
> ATOMIC_SPECIES
> H   1.00794 H.pbe-van_ak.UPF
> C  12.011   C.pbe-van_ak.UPF
> N  14.007   N.pbe-van_ak.UPF
> O  15.999   O.pbe-van_ak.UPF
> Fe 55.845   Fe.pbe-sp-van_ak.UPF
> ATOMIC_POSITIONS {angstrom}
> Fe       0.000000000   0.000000000   0.000000000 0 0 0
> N       -2.015936221   0.000000000   0.038768204
> N       -0.000013925  -2.014702715   0.046905328
> N        2.017269908   0.000000000   0.040458155
> N       -0.000013925   2.014652715   0.046905328
> C       -2.847040814   1.101001374   0.021528526
> C       -2.847040814  -1.101001374   0.021528526
> C       -1.099901325  -2.845127136   0.035557609
> C        1.099672879  -2.845475866   0.033358015
> C        2.848427407  -1.101716959   0.018059959
> C        2.848427407   1.101716959   0.018059959
> C        1.099672879   2.845475866   0.033358015
> C       -1.099901325   2.845127136   0.035557609
> C       -2.424089030   2.424582315   0.023330214
> C       -2.424089030  -2.424582315   0.023330214
> C        2.424273228  -2.425359652   0.019740116
> C        2.424273228   2.425359652   0.019740116
> C       -4.226164834   0.682755749   0.013419289
> C       -4.226164834  -0.682755749   0.013419289
> C       -0.682749799  -4.225087959   0.031048576
> C        0.682057949  -4.225434105   0.029188709
> C        4.226987371  -0.683186680   0.002120738
> C        4.226987371   0.683186680   0.002120738
> C        0.682057949   4.225434105   0.029188709
> C       -0.682749799   4.225087959   0.031048576
> H       -3.194929270   3.196716641   0.005583502
> H       -3.194929270  -3.196716641   0.005583502
> H        3.194370362  -3.198147171  -0.001036024
> H        3.194370362   3.198147171  -0.001036024
> H       -5.076004919   1.361487055   0.008732438
> H       -5.076004919  -1.361487055   0.008732438
> H       -1.361920855  -5.074396365   0.029488844
> H        1.360598646  -5.075191580   0.024602540
> H        5.077216872  -1.361288276  -0.011051138
> H        5.077216872   1.361288276  -0.011051138
> H        1.360598646   5.075191580   0.024602540
> H       -1.361920855   5.074396365   0.029488844
> N       -0.005537284   0.000000000   2.101372675
> C        1.071489062   0.000000000   2.880387333
> C       -1.100816954   0.000000000   2.946533090
> N        0.704089722   0.000000000   4.188705635
> C       -0.674259140   0.000000000   4.251114030
> C       -0.006438108   0.000000000  -1.731247148
> O       -0.017672814   0.000000000  -2.897017310
> H       -2.113804696   0.000000000   2.562350854
> H        2.100245178   0.000000000   2.539608359
> H        1.339496592   0.000000000   4.980002249
> H       -1.211591117   0.000000000   5.192219697
> K_POINTS
> 1
> 0.0 0.0 0.0 1.0
> 
> 
-- 
Andrea Dal Corso                    Tel. 0039-040-3787428
SISSA, Via Beirut 2/4               Fax. 0039-040-3787528
34014 Trieste (Italy)               e-mail: dalcorso at sissa.it