Dear Postnikov,
Thanks for your help ! As your advice, I changed the supercell (3 3 0)
into (4 4 0), however, new problem occured. I tried many parameters, but there
was always the same error:
"+ Segmentation fault "
I don't konw what this error means and how to eliminate it .
sincerely
Liu
____________________________________________________
NumberOfSpecies 1
%block chemicalspecieslabel
1 6 C
%endblock chemicalspecieslabel
PAO.BasisSize DZP
MeshCutoff 500.0 Ry/ 300Ry / 200 Ry / 100Ry
DM.MixingWeight 0.001 / 0.01/ 0.0001
DM.NumberPulay 3
DM.Tolerance 1.0d-4
%include FC.fdf
NumberOfAtoms 4
LatticeConstant 2.45951215 Ang
%block LatticeVectors
0.8660254 0.5 0.0
0.8660254 -0.5 0.0
0.0 0.0 8.0
%endblock LatticeVectors
AtomicCoordinatesFormat NotScaledCartesianAng
%block AtomicCoordinatesAndAtomicSpecies
-0.000007 0.000017 -0.127708 1 12.01
1.419987 0.000012 -0.127709 1 12.01
-0.000021 -0.000010 3.725312 1 12.01
1.419990 -0.000005 3.725319 1 12.01
%endblock AtomicCoordinatesAndAtomicSpecies
SuperCell_1 4
SuperCell_2 4
SuperCell_3 0
AtomicDispl 0.2 Bohr
BandLinesScale pi/a
%block BandLines
1 0.000 0.000 0.000 \Gamma
173 1.1547005 0.000 0.000 M
100 1.1547005 0.666666667 0.000 K
200 0.000 0.000 0.000 \Gamma
%endblock BandLines
_________________________________________________
My outfile also attached. Thanks for your help again!At 2011-10-10 04:38:35,[email protected] wrote: >> Dear siesta users, >> As we konw that there should be no negative value in phonon >> spectrum, but when I tried to draw the phonon spectrum of >> bilayer-graphene, there are always some negative intervals. I'am >> very confused about this. > >Dear Liu, > >such kind of "noise" in the vicinity of Gamma appears >when the force constants are not enough converged in the real space >(with distance to neighbors). >You use the supercell (3 3 0); will (4 4 0) be affordable? > >However! - the supercell size will affect just the vicinity of Gamma, >but NOT Gamma itself - which ought to be good even in (0 0 0) >supercell. I cannot judge from your plot whether you have >an imaginary frequency also at Gamma, or it is just traced so >through many points. If you have a problem at Gamma, >then you should fix it first, staying with a (0 0 0) supercell. >It must be due to insufficient MeshCutoff >(170 Ry you use is not that high). > >Best regards > >Andrei Postnikov > > > > >> My program attached. >> >> Best regards >> Liu >> _____________________________________________________________- >> >> NumberOfSpecies 1 >> >> >> >> %block chemicalspecieslabel >> >> 1 6 C >> >> %endblock chemicalspecieslabel >> >> >> >> PAO.BasisSize DZP >> >> >> >> MeshCutoff 170.0 Ry >> >> DM.MixingWeight 0.001 /0.01/0.1 >> >> DM.NumberPulay 3 >> >> DM.Tolerance 1.0d-5 >> >> %include FC.fdf >> >> NumberOfAtoms 4 >> >> LatticeConstant 2.45951215 Ang >> >> >> >> %block LatticeVectors >> >> 0.8660254 0.5 0.0 >> >> 0.8660254 -0.5 0.0 >> >> 0.0 0.0 8.0 >> >> %endblock LatticeVectors >> >> >> >> AtomicCoordinatesFormat NotScaledCartesianAng >> >> >> >> %block AtomicCoordinatesAndAtomicSpecies >> >> -0.000007 0.000017 -0.127708 1 12.01 >> >> 1.419987 0.000012 -0.127709 1 12.01 >> >> -0.000021 -0.000010 3.725312 1 12.01 >> >> 1.419990 -0.000005 3.725319 1 12.01 >> >> %endblock AtomicCoordinatesAndAtomicSpecies >> >> >> >> SuperCell_1 3 >> >> SuperCell_2 3 >> >> SuperCell_3 0 >> >> >> >> AtomicDispl 0.2 Bohr >> >> >> >> BandLinesScale pi/a >> >> %block BandLines >> >> 1 0.000 0.000 0.000 \Gamma >> >> 173 1.1547005 0.000 0.000 M >> >> 100 1.1547005 0.666666667 0.000 K >> >> 200 0.000 0.000 0.000 \Gamma >> >> %endblock BandLines >> >> >
2LayerGra.out
Description: Binary data
