Dear Siesta users,
I am having trouble getting the active IR vibrational modes for MoS2 and
WS2. More precisely, the phononic modes that the program generates for
me are up to frequencies of 450 cm-1. But in the literature, the
experimental IR vibrational modes are in the range 600-3000 cm-1. Why
can't I get these vibrational modes or what could I change in the fdf
file to get vibrational modes at higher frequencies?
Thank you!
SystemName MoS2
SystemLabel MoS2
NumberOfSpecies 2
%block ChemicalSpeciesLabel
1 16 S
2 42 Mo
%endblock ChemicalSpeciesLabel
NumberOfAtoms 18
LatticeConstant 1.8897268778 Bohr
%block LatticeVectors
9.5767200000 0.0000000000 0.0000000000
-1.5961200000 2.7645610000 0.0000000000
0.0000000000 0.0000000000 13.3782900000
%endblock LatticeVectors
AtomicCoordinatesFormat NotScaledCartesianBohr
%block AtomicCoordinatesAndAtomicSpecies
-3.0169018247 1.7418097833 6.3203288007 2
-6.0317907678 3.4824553391 18.9609853909 2
-3.0165598445 1.7416118882 16.0098457586 1
-6.0321327480 3.4826534433 9.2714681802 1
-3.0165597841 1.7416118882 21.9121257817 1
-6.0321328083 3.4826534433 3.3691889156 1
3.0155599036 1.7418097833 6.3203288007 2
0.0006709606 3.4824553391 18.9609853909 2
3.0159018839 1.7416118882 16.0098457586 1
0.0003289803 3.4826534433 9.2714681802 1
3.0159019442 1.7416118882 21.9121257817 1
0.0003289200 3.4826534433 3.3691889156 1
9.0480216319 1.7418097833 6.3203288007 2
6.0331326889 3.4824553391 18.9609853909 2
9.0483636122 1.7416118882 16.0098457586 1
6.0327907086 3.4826534433 9.2714681802 1
9.0483636725 1.7416118882 21.9121257817 1
6.0327906483 3.4826534433 3.3691889156 1
%endblock AtomicCoordinatesAndAtomicSpecies
MD.TypeOfRun FC
MD.FCfirst 7
MD.FClast 12
MD.FCdispl 0.0400000000 Bohr
PAO.BasisSize DZP
MeshCutoff 200 Ry
%block kgrid_Monkhorst_Pack
5 0 0 0.5
0 5 0 0.5
0 0 1 0.5
%endblock kgrid_Monkhorst_Pack
%block BandLines
1 0.000000 0.000000 0.00000 \Gamma
20 0.500000 0.000000 0.00000 M
30 0.333333 0.333333 0.00000 K
20 0.000000 0.000000 0.00000 \Gamma
%endblock BandLines
BornCharge true
%block PolarizationGrids
10 4 4
4 10 4
4 4 10
%endblock PolarizationGrids
XC.Functional LDA
XC.Authors CA
DM.NumberPulay 5
DM.MixingWeight 0.01
DM.Tolerance 1.d-5
MaxSCFIterations 1000
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SIESTA is supported by the Spanish Research Agency (AEI) and by the European
H2020 MaX Centre of Excellence (http://www.max-centre.eu/)
