molecular dynamics
Posted: Tue Apr 15, 2008 6:30 pm
Dear all,
I have started learning molecular dynamics and it seems that EDIFFG is not applicable for IBRION=0.I want to know what is the tolerance criterion for this type of calculation?I mean to say that if I dont specify EDIFFG then what should be my value of NSW?
when we do normal calculation we use to set NSW to such a value so that system reaches the specified EDIFFG value much before of final ionic step mentioned by NSW.
2ndly I did three benchmark molecular dynamics run with NSW=30, 100, 1000 respectively and in all the three runs final forces on the atoms were reasonably high.So which result should I believe?Can anyone help me out of this?
Lastly if I want to just heat a system to a temperature say 300K what should be the value of SMASS?Is there any tricks to set this SMASS value?I have set my INCAR as given below........
PREC = Normal ! standard precision
ENMAX = 400 ! cutoff should be set manually
ISMEAR = 0 ; SIGMA = 0.1
IBRION = 0 ! molecular dynamics
NSW = 100 ! 100 steps
POTIM = 1.0 ! timestep 1 fs
SMASS = -3 ! Nose Hoover thermostat
TEBEG = 300 ; TEEND = 300 ! temperature
Can anyone comment if I have set anything wrong in my INCAR file?I have just started learning this and that's why I want some comments on this....
thaks to all,
I have started learning molecular dynamics and it seems that EDIFFG is not applicable for IBRION=0.I want to know what is the tolerance criterion for this type of calculation?I mean to say that if I dont specify EDIFFG then what should be my value of NSW?
when we do normal calculation we use to set NSW to such a value so that system reaches the specified EDIFFG value much before of final ionic step mentioned by NSW.
2ndly I did three benchmark molecular dynamics run with NSW=30, 100, 1000 respectively and in all the three runs final forces on the atoms were reasonably high.So which result should I believe?Can anyone help me out of this?
Lastly if I want to just heat a system to a temperature say 300K what should be the value of SMASS?Is there any tricks to set this SMASS value?I have set my INCAR as given below........
PREC = Normal ! standard precision
ENMAX = 400 ! cutoff should be set manually
ISMEAR = 0 ; SIGMA = 0.1
IBRION = 0 ! molecular dynamics
NSW = 100 ! 100 steps
POTIM = 1.0 ! timestep 1 fs
SMASS = -3 ! Nose Hoover thermostat
TEBEG = 300 ; TEEND = 300 ! temperature
Can anyone comment if I have set anything wrong in my INCAR file?I have just started learning this and that's why I want some comments on this....
thaks to all,