Dear SIESTA Users, Hope you are doing well. I was trying to do a Molecular Dynamics (MD) simulation using SIESTA. I was trying to do a NVT MD Simulation using the Nose thermostat. My structure is a nanotube structure extended in the z-direction. The problem that I am facing is that the temperature is increasing steadily with each MD step. After around 50 steps, the temperature reached around 1500 K and then dropped down to 400 K and then the calculation stopped after around 130 steps saying that the SCF did not converge. I wanted to do the MD simulation at room temperature. I tried with several other thermostats, for example Verlet, Anneal etc. But in each case the same scenario has been observed. Can anyone suggest to me what I should do? I am using the following input parameters for my calculations. I have 80 atoms in my system.
%block kgrid_Monkhorst_Pack 1 0 0 0.0 0 1 0 0.0 0 0 10 0.0 %endblock kgrid_Monkhorst_Pack PAO.BasisType split PAO.SplitNorm 0.25 PAO.BasisSizes DZP SpinPolarized F XC.functional GGA XC.authors PBE SolutionMethod diagon ElectronicTemperature 700 K OccupationFunction MP OccupationMPOrder 2 VariableCell F Mesh.Cutoff 450 Ry ############################################################### # CG BLOCK ############################################################### MD.TypeOfRun Nose MD.InitialTimeStep 1 MD.FinalTimeStep 2000 MD.LengthTimeStep 1.0 fs MD.InitialTemperature 300 K MD.TargetTemperature 300 K MD.NoseMass 100 Ry*fs**2 WriteCoorStep T WriteMDHistory T WriteMDXmol T MD.VariableCell F WriteForces T MD.UseSaveCG T MD.UseSaveXV T ############################################################## UseSaveData T WriteMullikenPop 1 WriteDM T WriteCoorXmol T ############################################################### # DM BLOCK # ############################################################### MaxSCFIterations 10000 DM.MixingWeight 0.01 DM.Tolerance 1.d-2 DM.Require.Energy.Convergence T DM.Energy.Tolerance 1.d-3 eV DM.UseSaveDM T DM.NumberPulay 7 ############################################################### Thank you, With regards, Suman Chowdhury
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