[Pw_forum] (no subject)

[Osmair Vital Osmair]

Dear users,
I am trying to calculate critical temperature for Titanium. I used the
following
files:
Ti.scf.in
 &control
    calculation='scf'
    restart_mode='from_scratch',
    prefix='Ti',
    pseudo_dir = './',
    outdir='./'
 /
 &system
    ibrav =  4,
    celldm(1) = 5.576203,
    celldm(3) = 1.587874,
    nat = 1,
    ntyp = 1,
    occupations = 'smearing',
    degauss = 0.03,
    smearing = 'cold',
    ecutwfc = 60.0,
    la2F = .true.,
 /
 &electrons
     mixing_beta = 0.7,
     conv_thr =  1.0d-15,
     diagonalization = 'cg',
/
ATOMIC_SPECIES
 Ti  47.88 Ti.pbe-sp-hgh.UPF
ATOMIC_POSITIONS ANGSTROM
 Ti 0.33333 0.66667 0.25000
K_POINTS {automatic}
8 8 8 0 0 0

Question 1) The calculation is finished without error, but in the output
file
has the message  "No symmetry found
          (note: 23 additional sym.ops. were found but ignored
           their fractional translations are incommensurate with FFT grid)".
This is very interesting because I tested various inputs with different
elements with hexagonal structure (Zr, Tc, Re...) the same message appear.
So, is there any
problem or bug with the ibrav = 4 (hexagonal)?
In addiction, in the ph.x calculation using the input below, I found
negative frequencies, these frequencies can be attributed to this message?

Question 2)
After the scf calculation, I performed ph.x using the file:
 &inputph
  tr2_ph=1.0d-16,
  prefix='Ti',
  fildvscf='aldv',
  amass(1)=47.88,
  outdir='./',
  fildyn='Ti.dyn',
  electron_phonon='interpolated',
  trans=.true.,
  ldisp=.true.
  nq1=4, nq2=4, nq3=4
 /
In this calculation, the file Ti.dy0 has 36 points and it was generate
36 elph.* files. However, the kpoints.x generate 50 k-points:
bravais lattice  >> 4
     filout [mesh_k]  >>
     enter celldm(3)  >> 1.587874
     mesh: n1 n2 n3   >> 8 8 8
     mesh: k1 k2 k3 (0 no shift, 1 shifted)  >> 0 0 0
     write all k? [f] >>
     # of k-points   ==    50  of   512

If I use mesh: n1 n2 n3   >> 4 4 4, I have 12 k-points
So, I expected that the number o k-points generated by the kpoints.x is the
same of the obtained by the ph.x. Is this corrected and how can I improve
this?

Thanks in advance.
Osmair V. Oliveira
Brazil
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