[DFTB-Plus-User] MD_NVE job problem

nkarimov nkarimov at uci.edu
Mon Jun 4 21:35:39 CEST 2018


Hello,

I am a new user. I try to perform test calculations of MD (NVE) for an 
acrylic acid molecule.
But there is a problem: after a few steps the molecule is splitting up 
into atoms.
Could you take a look at my input file and give me some suggestions 
about it?

Geometry = GenFormat {
9 C
   H O C

       1  2        -0.6298552075   -1.2915412252    0.0473193564
       2  3        -0.4850436821   -0.0891284588    0.0064915606
       3  2        -1.5249349504    0.7707759355   -0.0252152106
       4  3         0.8066493245    0.6320056300   -0.0155700879
       5  3         1.9563829759   -0.0445621962    0.0153469673
       6  1         0.7693502708    1.7174607721   -0.0570422509
       7  1         2.9149072107    0.4673418967   -0.0000219901
       8  1        1.9496309947   -1.1319992807    0.0568836905
       9  1        -2.3370722554    0.2363787099   -0.0085400376
}

Driver = VelocityVerlet {
   MovedAtoms = 1:-1
   #ConvergentForcesOnly = No
   Steps = 1000
   TimeStep = 5
   #Thermostat = NoseHoover{
   #Temperature[Kelvin] = 300
   #CouplingStrength=500
   #}
   Thermostat = None {
   InitialTemperature = 300.0
   }
   OutputPrefix = "md_nvt_1.out"
}

Hamiltonian = DFTB {
   #Dispersion = DFTD3 {}
   Charge = 0
   #ForceEvaluation = 'Dynamics'
   SCC = Yes
   MaxSCCIterations = 250
   SCCTolerance = 1.0e-4
   Mixer = Broyden {
   MixingParameter = 0.3
   }
   Differentiation = Richardson {}
   SlaterKosterFiles = Type2FileNames {
     Prefix = "/export/home/nkarimov/DFTB/mio-1-1/"
     Separator = "-"
     Suffix = ".skf"
   }
   MaxAngularMomentum {
     C = "p"
     O = "p"
     H = "s"
   }
   Filling = Fermi {
     Temperature [Kelvin] = 300.0
   }
}

Options {}

ParserOptions {
   ParserVersion = 5
}


Thanks,
Natalia Karimova

Assistant Research Scientist I
Chemistry Department
University of California, Irvine



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