[Pw_forum] Electron-Phonon: Two questions

[Miguel Martínez Canales]

Dear Dr. Gianozzi,

Maybe this has something to do with the other el-ph thread. Anyway, with the
test job I'm providing, I get the following nscf output. Am I using a kpoint 
grid that is too large?

Job:

[...]
# self-consistent calculation
cat > al.scf.in << EOF
  &control
     calculation='scf'
     restart_mode='from_scratch',
     tstress = .true.
     tprnfor = .true.
     prefix='al',
     pseudo_dir = '$PSEUDO_DIR/',
     outdir='$TMP_DIR/'
  /
  &system
     ibrav=  2, celldm(1) =7.603, nat=  1, ntyp= 1,
     ecutwfc =40.0,
     occupations='smearing', smearing='gauss', degauss=0.04
  /
  &electrons
     conv_thr =  1.0d-8
     mixing_beta = 0.7
  /
ATOMIC_SPECIES
  Al  26.9815  Al.pbe-n-van.UPF
ATOMIC_POSITIONS
  Al 0.00 0.00 0.00
K_POINTS {automatic}
  32 32 32  1 1 1
EOF
$ECHO "  running the scf calculation...\c"
$PW_COMMAND < al.scf.in > al.scf.out
$ECHO " done"

cat > al.nscf.in << EOF
  &control
     calculation='phonon'
     restart_mode='from_scratch',
     prefix='al',
     pseudo_dir = '$PSEUDO_DIR/',
     outdir='$TMP_DIR/'
  /
  &system
     ibrav=  2, celldm(1) =7.603, nat=  1, ntyp= 1,
     ecutwfc =40.0,
     occupations='smearing', smearing='gauss', degauss=0.04
  /
  &electrons
     conv_thr =  1.0d-8
  /
  &phonon
     xqq(1) = -0.125, xqq(2) = -0.125, xqq(3) = -0.125
  /
ATOMIC_SPECIES
  Al  26.9815  Al.pbe-n-van.UPF
ATOMIC_POSITIONS
  Al 0.00 0.00 0.00
K_POINTS {automatic}
  32 32 32  1 1 1
EOF
$ECHO "  running the nscf calculation at q=$qpoint...\c"
$PW_COMMAND < al.nscf.in >> al.nscf.out
$ECHO " done"
[...]

It follows with a ph.x input file with elph.and.trans=.true. I won't submit 
this, as the error I get is in the nscf run. I was using just 2gb of ram. The 
nscf output is:

      Program PWSCF     v.2.1.5  starts ...
      Today is  5Oct2005 at  3:31:22

      Parallel version (MPI)

      Number of processors in use:       2
      R & G space division:  nprocp =    2

      Ultrasoft (Vanderbilt) Pseudopotentials

      Current dimensions of program pwscf are:
      ntypx =10   npk =40000  lmax = 3
      nchix = 6  ndmx = 2000  nbrx =14 nqfx = 8

  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
      from set_kplusq : error #     22880
      too many k points
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

      stopping ...

Thanks again,

Miguel


Paolo Giannozzi wrote:
> On Thursday 22 September 2005 16:34, Miguel Martínez Canales wrote:
> 
> 
>>- One of the calculations, although it yields results, gives me the
>>following error message:
>>
>>      task #         0
>>      from set_kplusq : error #         0
>>      too many k points
>>
>>should I be worried?
> 
> 
> maybe: it is a very weird error. Could you please provide a test job?
> 
> 
>>- On the second non-selfconsistent run, with a dense grid [..]
>>sometimes kpoint counting surpasses k(9999) and k(****) follows.
>>Is this the source of the previous error ?
> 
> 
> most likely, no
> 
> Paolo
> 

-- 
----------------------------------------
Miguel Martínez Canales
    Dto. Física de la Materia Condensada
    UPV/EHU
    Facultad de Ciencia y Tecnología
    Apdo. 644
    48080 Bilbao (Spain)
Fax:  +34 94 601 3500
Tlf:  +34 94 601 5437
----------------------------------------

2005 International Year of Physics