Dear vasp users:
I am MD learner, and I wanna to use MD simulation to determin the structure of Our system(at least 128 atoms, or 432 atoms or more).
I read mannual, the MD parameters it suggests are:
==================
ENCUT = 150 eV ! energy cutoff (opt)
IALGO = 48 ! RMM-DIIS algorithm for electrons
LREAL = A ! evaluate projection operators in real space
NELMIN = 4 ! do a minimum of four electronic steps
BMIX = 2.0 ! mixing parameter
MAXMIX = 50 ! keep dielectric function between ionic movements
Ionic Relaxation
ISYM = 0 ! switch of symmetry
NSW = 100 ! number of steps for IOM
NBLOCK = 1 ; KBLOCK = 100
SMASS = 2.0 ! Nose mass-parameter (am)
POTIM = 3.00 ! time-step for ion-motion
TEBEG = 573 ! temperature
PC-function
APACO = 10.0 ! distance for P.C.
===============
Since i wanna determin the structure, I have to simulate the experimental process by MD, which means I should simulate increasing temperature from 0k to above the melting point(say 2000k), and then cool the system to 0k with a certain cooling rate.
I don't think the parameters above can simulate these two process(the heating process and cooling process)
So my questions are:
How do set the parameters to simulate this two process ?
Thanks a lot:)
<span class='smallblacktext'>[ Edited ]</span>
MD determin the structure
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MD determin the structure
Last edited by vasp16888 on Wed Aug 11, 2010 8:49 am, edited 1 time in total.
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MD determin the structure
if you want to determin the DFT ground state structure, please use IBRION 1 (if you start close to the minimum already), 2 or 3.
If you really want to do simulated annealing, please set TEBEG and TEEND
If you really want to do simulated annealing, please set TEBEG and TEEND
Last edited by admin on Thu Aug 26, 2010 2:32 pm, edited 1 time in total.
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MD determin the structure
[quote="red"]So please give me some suggestion about how to improve the speed of MD simulation( I know for ab initio MD, the speed is way much slower than classical MD). Any suggestions about improving the speed of MD will be greatly appreciated:)[/color]
Thanks in advance!
Thanks in advance!
Last edited by vasp16888 on Mon Aug 30, 2010 8:59 am, edited 1 time in total.
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[/align]AB INITIO STUDY OF MAGNETIC MATERIALS