Dear SIESTA users,
I am having problems with constrained dynamics in SIESTA. I am using z-martix
to describe the geometry of the system (for testing purposes I am simulating
H2O2 molecule) and I want to keep the O-O distance constant. Here is how my
input file looks like:
SystemName h2o2
SystemLabel h2o2
NumberOfAtoms 4
NumberOfSpecies 2
%block Chemical_Species_Label
1 8 O
2 1 H
%endblock Chemical_Species_Label
PAO.BasisSize DZP
NetCharge 0.000000
AtomicCoordinatesFormat Ang
AtomicCoorFormatOut Ang
ZM.UnitsLength Ang
Zm.UnitsAngle deg
%block Zmatrix
molecule
1 0 0 0 2.03222100 2.89235500 2.67244000 1 1 1 ###O1
1 1 0 0 const 89.44993852 8.65938260 0 1 1 ###O2
2 2 1 0 0.96 109.471 -115.964 1 1 1 ###H1
cartesian
2 1.836000 2.040004 3.060007 1 1 1 ###H2
constants
const 1.49
%endblock Zmatrix
%endblock AtomicCoordinatesAndAtomicSpecies
LatticeConstant 1.0 Ang
%block LatticeParameters
6.000 6.000 6.000 90.0 90.0 90.0
%endblock LatticeParameters
kgrid_cutoff 0.000000 Ang
XC.functional GGA
XC.Authors PBE
SpinPolarized .false.
MeshCutoff 100 Ry
MaxSCFIterations 50
DM.MixingWeight 0.05
DM.Tolerance 0.0001
DM.NumberPulay 10
SolutionMethod diagon
ElectronicTemperature 5.0 K
MD.TypeOfRun Nose
MD.InitialTimeStep 1
MD.FinalTimeStep 50
MD.LengthTimeStep 1.0 fs
MD.InitialTemperature 350.0 K
MD.TargetTemperature 350.0 K
WriteCoorInitial .true.
WriteCoorStep .true.
Note the '0' value in the line corresponding to the 'const' constant defined
below.
The problem is - distance is not constant but it is changing during the run.
What am I doing wrong?
Cheers,
Bartek
