|||
6. Warning: symmetry operation # N not allowed
This is not an error.
If a symmetry operation contains a fractional translation that is incompatible with the FFT grid, it is discarded in order to prevent problems with symmetrization.
Typical fractional translations are 1/2 or 1/3 of a lattice vector. If the FFT grid dimension along that direction is not divisible respectively by 2 or by 3, the symmetry operation will not transform the FFT grid into itself.
Solution: you can either force your FFT grid to be commensurate with fractional translation (set variables nr1, nr2, nr3 to suitable values), or set variable use_all_frac to .true., in namelist &SYSTEM. Note however that the latter is incompatible with hybrid functionals and with phonon calculations.
Eigenvectors exchange needed 1 34
Eigenvectors exchange needed 1 35
Eigenvectors exchange needed 1 36
Calculation of q = 0.0000000 0.0000000 0.0000000
Possibly too few bands at point 1 0.00000 0.00000 0.00000
Possibly too few bands at point 2 0.00000 0.00000 0.09091
Possibly too few bands at point 7 0.00000 0.09091 0.09091
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Error in routine set_irr_sym_new (122):
wrong representation
The routine that checks the symmetry of the modes has been partiallyrevised. Now it stops the ph.x run when it does not recognize the symmetry of a modes of the random matrix. You can force continuation by setting search_sym=.false..
&inputph
tr2_ph=1.0d-12,
prefix='$name',
amass(1)=1.008,
amass(2)=44.955910,
search_sym=.false.
outdir='$TMP_DIR',
fildyn='$name.dyn_$a',
/
0.0 0.0 0.0
EOF
3. Possibly too few bands at point 1 0.00000 0.00000 0.00000
nbnd= 30
Just set up manually bands number "nbnd" in your scf-input file. The message means that nbnd used by default is not sufficient. If you use an old version set up nbnd in nscf-file.
nbnd | INTEGER |
---|---|
Default: | for an insulator, nbnd = number of valence bands (nbnd = # of electrons /2); for a metal, 20% more (minimum 4 more) |
number of electronic states (bands) to be calculated.Note that in spin-polarized calculations the number ofk-point, not the number of bands per k-point, is doubled |
Phonon anomalies in metals are related to Fermi surface nesting.You therefore need to describe correctly the Fermi surface. This imply looking for the limit where degauss->0 (mantaininggood convergence with respect BZ sampling) I suggest you keep a reasonable cutoff (35 or less should be OKfor Pt) and study instead the phonon dispersion behaviour with respect the degaussvalue. Proceed as follow: For each value of degauss you should increase the k point meshuntil frequencies are stable. Look for the behavior of the converged frequency as you reducedegauss. For not anomalous frequencies things should be ratherinsensitive to these details but or the anomalous ones you should see the difference. Have a look to the following two references: S. de Gironcoli, Lattice Dynamics of Metals fromDensity-Functional Perturbation Theory, Phys. Rev. B 51, 6773 (1995). C. Bungaro, S. de Gironcoli, and S. Baroni, Theory of theanomalous Rayleigh dispersion at H/W(110) surfaces, Phys. Rev. Lett.77, 2491 (1996). all the best stefano
1.pw.x stops during variable-cell optimization in checkallsym with non orthogonal operation errorVariable-cell optimization may occasionally break the starting symmetry of the cell. When this happens, the run is stopped because the number of k-points calculated for the starting configuration may no longer be suitable. Possible solutions:
start with a nonsymmetric cell;
use a symmetry-conserving algorithm: the Wentzcovitch algorithm (cell dynamics='damp-w') should not break the symmetry.
cell_dynamics | CHARACTER |
---|---|
Specify the type of dynamics for the cell.For different type of calculation different possibilitiesare allowed and different default values apply:CASE ( calculation = 'vc-relax' ) 'none': no dynamics 'sd': steepest descent ( not implemented ) 'damp-pr': damped (Beeman) dynamics of the Parrinello-Rahman extended lagrangian 'damp-w': damped (Beeman) dynamics of the new Wentzcovitch extended lagrangian 'bfgs': BFGS quasi-newton algorithm (default) ion_dynamics must be 'bfgs' tooCASE ( calculation = 'vc-md' ) 'none': no dynamics 'pr': (Beeman) molecular dynamics of the Parrinello-Rahman extended lagrangian 'w': (Beeman) molecular dynamics of the new Wentzcovitch extended lagrangian |
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