zero point energy

Queries about input and output files, running specific calculations, etc.


Moderators: Global Moderator, Moderator

Post Reply
Message
Author
hlzya
Newbie
Newbie
Posts: 12
Joined: Fri Mar 17, 2006 3:12 pm
License Nr.: 641

zero point energy

#1 Post by hlzya » Tue Mar 21, 2006 2:16 am

Hello,

I want to calculate the zero point energy for my system in order to compare my theoretical results with experimental data.Firstly, I have performed the geometry optimization calculations for my system. And secondly, I want to calculate the normal mode of my system. I wonder if my INCAR listed below is right, and if this kind of calculation will change my geometry again.

Thanks a lot!

Start parameter for this Run:
ISTART = 0
ICHARG = 2
INIWAV = 1
Electronic Relaxation:
ENCUT = 350
ENAUG = 550
PREC = Accurate
IALGO = 38
NELM = 60
NELMIN = 4
NELMDL = -5
EDIFF = 1E-05
NBANDS = 256
GGA = 91
VOSKOWN = 1
Ionic Relaxation:
EDIFFG = 1E-04
NSW = 1 -------------------> Do NSW=1 and ISIF =2 make me optimize the geometry again?
IBRION = 5
ISIF = 2
NFREE = 2
DOS related values:
SIGMA = 0.1
ISMEAR = 1
Spin polarized:
ISPIN = 2
Last edited by hlzya on Tue Mar 21, 2006 2:16 am, edited 1 time in total.

admin
Administrator
Administrator
Posts: 2921
Joined: Tue Aug 03, 2004 8:18 am
License Nr.: 458

zero point energy

#2 Post by admin » Thu Mar 23, 2006 2:55 pm

no, if IBRION=5, no further geometry optimisation step is taken, the displacements of the atoms are just to determine the Hessian matrix.
Please do not forget to set POTIM to a small value which ensures that the displacements are in the harmonic regime
Last edited by admin on Thu Mar 23, 2006 2:55 pm, edited 1 time in total.

hlzya
Newbie
Newbie
Posts: 12
Joined: Fri Mar 17, 2006 3:12 pm
License Nr.: 641

zero point energy

#3 Post by hlzya » Sat Mar 25, 2006 12:16 pm

Thank you for your reply! As for a Ni surface with a CH4 above it, what should I set POTIM to? Thanks!
Last edited by hlzya on Sat Mar 25, 2006 12:16 pm, edited 1 time in total.

Post Reply