[Pw_forum] Phonon crash

Miguel Martínez Canales wmbmacam at lg.ehu.es
Wed Mar 14 10:54:55 CET 2007

Dear fellows,

I have found that, when running a phonon calculation under certain 
conditions, it crashes. More concretely, on fcc systems (I haven't checked 
diamond structures) if the scf run uses a 20 20 20 monkhorst-pack grid and 
the phonon calculation uses ldisp=.true. for a 8*8*8 regular grid the 
phonon run will crash at dyn23 (q = 0.625 -0.375  0.875). The last lines of 
the phonon output are:

      Calculation of q =   0.6250 -0.3750  0.8750

      from set_kplusq : error #     32000
      too many k points

      stopping ...

It really puzzles me that it stops on the 23rd point, and not sooner. Maybe 
it's related to the star of q?

If I specify this point by hand, doing a nscf run and then a phonon run at 
that qpoint, it will also crash. It depends neither on the lattice 
parametre, nor the the pseudpotential (I've done it with Na LDA, Li LDA and 
Li PBE). It won't crash if I reduce the k-point grid, and it won't crash 
with the same grid on a bcc lattice.

I am using espresso-3.2.1 plus the patch that Paolo submitted to make 
-npool work with ph.x. It's been compiled with ifort 8.1 and mkl 9.0 in an 
itanium 2 machine. Any ideas?

Thanks for your comments,


In case the input is relevant, I attach it:

# self-consistent calculation
cat > na.scf.in << EOF
     tstress = .true.
     tprnfor = .true.
     pseudo_dir = '$PSEUDO_DIR/',
     ibrav=  2, celldm(1) = $alat , nat=  1, ntyp= 1,
     ecutwfc = 30.0
     occupations='smearing', smearing='m-p', degauss= 0.010
     conv_thr =  1.0d-8
     mixing_beta = 0.7
  Na  22.989768  Na.pz-n-vbc.UPF
  Na 0.00 0.00 0.00
K_POINTS {automatic}
  20 20 20   1 1 1
$ECHO "  running the scf calculation...\c"
$PW_COMMAND < na.scf.in > na.scf.out
$ECHO " done"

# phonon calculation
cat > na.ph.in << EOF
phonons of Na
   nq1=8, nq2=8, nq3=8
$ECHO "  running the phonon calculation ...\c"
$PH_COMMAND < na.ph.in > na.ph.out
$ECHO " done"

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

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