Hi,
I am using Siesta 3.2 and ran into a strange problem.
I simulate a water molecule and the Mulliken charges are wrong. It shows
that the oxygen atom is positively charged and the two hydrogens are
negatively charged. The Hirshfeld and Voronoi populations are fine. Did I
run into a bug?
*input.fdf*
NumberOfAtoms 3
NumberOfSpecies 4
%block ChemicalSpeciesLabel
1 13 Al
2 14 Si
3 8 O
4 1 H
%endblock ChemicalSpeciesLabel
PAO.BasisType nodes
%block PAO.BasisSizes
Al DZP
Si DZP
O DZP
H DZP
%endblock PAO.BasisSizes
XC.functional GGA
XC.authors PBE
# SCF options
MaxSCFIterations 200
DM.MixingWeight 0.25 # New DM amount for next SCF cycle
DM.Tolerance 1.d-6 # Tolerance in maximum difference
SolutionMethod diagon # OrderN or Diagon
MeshCutoff 400 Ry
DM.Require.Energy.Convergence .true.
DM.Energy.Tolerance 1.d-6 eV
MD.TypeOfRun CG
MD.NumCGsteps 100
MD.InitialTemperature 300.0 K
MD.TargetTemperature 300.0 K
WriteHirshfeldPop .true.
WriteVoronoiPop .true.
WriteMullikenPop 1
LatticeConstant 1 Ang
%block LatticeVectors
9.5160000000 0.0000000000 0.0000000000
-4.7580000000 8.2411000000 0.0000000000
0.0000000000 0.0000000000 48.2792733630
%endblock LatticeVectors
WarningMinimumAtiomicDistance 1.0 Ang
AtomicCoordinatesFormat NotScaledCartesianAng
%block AtomicCoordinatesAndAtomicSpecies < Coord.fdf
*Coord.fdf*
5.265981 -1.943725 -6.378528 3
4.222545 -1.943725 -6.378528 4
5.612381 -0.997652 -6.378528 4
*Output (excerpts)*
mulliken: Mulliken Atomic and Orbital Populations:
Species: O
Atom Qatom Qorb
2s 2s 2py 2pz 2px 2py 2pz 2px
2Pdxy 2Pdyz 2Pdz2 2Pdxz 2Pdx2-y2
1 5.764 1.436 -0.027 1.363 1.793 1.235 -0.023 -0.003 -0.034
0.003 0.002 0.005 0.001 0.014
Species: H
Atom Qatom Qorb
1s 1s 1Ppy 1Ppz 1Ppx
2 1.118 0.845 0.036 0.063 0.104 0.070
3 1.118 0.845 0.036 0.091 0.104 0.042
Hirshfeld Net Atomic Populations:
Atom # Qatom Species
1 -0.234 O
2 0.117 H
3 0.117 H
Voronoi Net Atomic Populations:
Atom # Qatom Species
1 -0.171 O
2 0.086 H
3 0.085 H
Best Regards,
Dan
