Dear All,
Thank you very much for your time!
I am puzzled about the set of LatticeVectors in the input file. Maybe the
fellow question is too simple, but it's really a problem for me to understand
it.
For example, when you do a bulk calculation of Au leads (111). What do you
think the difference between the different set of lattice vectors, set as
follow.
one:
%block LatticeVectors
9.571313000 0.000000000 0.0000000000
0.000000000 14.01989100 0.0000000000
0.000000000 0.000000000 7.0691600000
%endblock LatticeVectors
second:
%block LatticeVectors
4.3289600000 -8.4979700000 0.0000000000
4.3289600000 8.4979700000 0.0000000000
0.0000000000 0.0000000000 7.0691600000
%endblock LatticeVectors
As we known that the Au is FCC, it seems that the second choice is better. But
as in some case, we select some part of system, for example Au, to represent
the period structure of bulk system. What's the physical view of this kind?
Could you give some explain?
Thank you very much in advace!
Jackie Wan,
The input file:
=============================================
# Sample file for programs SIESTA
SystemName Au-lead # Descriptive name of the system
SystemLabel Au # Short name for naming files
NumberOfAtoms 27 # Number of atoms
NumberOfSpecies 1 # Number of species
PAO.BasisType split # Type of basis ('nones', 'nonodes', 'split')
PAO.SplitNorm 0.15 # Amount of norm carried by the second zeta
%block ChemicalSpeciesLabel
1 79 Au
%endblock ChemicalSpeciesLabel
%block PAO.Basis
Au 1
n=6 0 1
6.0
%endblock PAO.Basis
LatticeConstant 1.0 Ang
%block LatticeVectors
4.3289600000 -8.4979700000 0.0000000000
4.3289600000 8.4979700000 0.0000000000
0.0000000000 0.0000000000 7.0691600000
%endblock LatticeVectors
AtomicCoordinatesFormat Ang
%block AtomicCoordinatesAndAtomicSpecies
1.4429860000 0.8331080000 0.0000000000 1
2.8859710000 -1.6662140000 0.0000000000 1
4.3289560000 -4.1655360000 0.0000000000 1
2.8859710000 3.3324300000 0.0000000000 1
4.3289560000 0.8331080000 0.0000000000 1
5.7719410000 -1.6662140000 0.0000000000 1
4.3289560000 5.8317520000 0.0000000000 1
5.7719410000 3.3324300000 0.0000000000 1
7.2149260000 0.8331080000 0.0000000000 1
1.4429860000 -0.8331080000 2.3563870000 1
2.8859710000 -3.3324300000 2.3563870000 1
4.3289560000 -5.8317520000 2.3563870000 1
2.8859710000 1.6662140000 2.3563870000 1
4.3289560000 -0.8331080000 2.3563870000 1
5.7719410000 -3.3324300000 2.3563870000 1
4.3289560000 4.1655360000 2.3563870000 1
5.7719410000 1.6662140000 2.3563870000 1
7.2149260000 -0.8331080000 2.3563870000 1
0.0000000000 0.0000000000 4.7127680000 1
1.4429850000 -2.4993220000 4.7127680000 1
2.8859700000 -4.9986440000 4.7127680000 1
1.4429850000 2.4993220000 4.7127680000 1
2.8859700000 0.0000000000 4.7127680000 1
4.3289550000 -2.4993220000 4.7127680000 1
2.8859700000 4.9986440000 4.7127680000 1
4.3289550000 2.4993220000 4.7127680000 1
5.7719400000 0.0000000000 4.7127680000 1
%endblock AtomicCoordinatesAndAtomicSpecies
%block kgrid_Monkhorst_Pack
2 0 0 0.0
0 2 0 0.0
0 0 3 0.0
%endblock kgrid_Monkhorst_Pack
BandLinesScale ReciprocalLatticeVectors
xc.functional GGA # 'LDA', 'GGA'
xc.authors PBE #'CA'='PZ', 'PW92', 'PBE'
SpinPolarized F # 'T', 'F'
FixSpin F
TotalSpin 0.0
NonCollinearSpin F # 'T', 'F'
MeshCutoff 180. Ry # Equivalent plane wave cutoff for the grid
MaxSCFIterations 300
DM.MixingWeight 0.05
DM.Tolerance 1.0E-5
NeglNonOverlapInt T # 'F'=do not neglect
SolutionMethod diagon
ElectronicTemperature 300 K # Default value
============================================== end of input file
