Hi,
Actually, I am trying to calculate the Density of States of a carbon nanotube. However, I always have this WARNING (stress and forces are not correct (second dervivative of E(xc) not defined) !!!).
What I do not understand is which parameter I have to change not to have this Warning again?
Please, let me know if someone have an idea about my problem,
Thank you,
Damien
My Incar file is the following:
Startparameter for this Run:
NWRITE = 2;! LPETIM=F write-flag & timer
ISTART = 0;! job : 0-new 1-cont 2-samecut
ICHARG = 11;
LCHARG = T;
Electronic Relaxation 10
PREC = HIGH
NELM = 15 ;
EDIFF = 1E-05 ! stopping-criterion for ELM
BMIX = 3.00 ;
Ionic Relaxation
EDIFFG = -1E-04
NSW = 0 ! number of steps for IOM
NBLOCK = 1;! KBLOCK = 5 inner block; outer block
IBRION = 1 ! ionic relax: 0-MD 1-quasi-New 2-CG
ISIF = 2 ! stress and relaxation
ISYM = 2
IWAVPR = 2 ! prediction: 0-non 1-charg 2-wave 3-comb
LCORR = T ! Harris-correction to forces
POTIM = 0.20 ! time-step for ion-motion
TEBEG = 0.001 ; ! TEEND=1873.0 initial temperature
SMASS = 3.00 ! Nose mass-parameter (am)
GGA = 91;
VOSKOWN = 1;
DOS related values:
ISMEAR = 0;
SIGMA = 0.1;
RWIGS = 1.3;
ectronic Relaxation 2
ALGO = N
LDIAG = T ! sub-space diagonalisation
LREAL = T ! real-space projection
NPAR=1;
WARNING: stress and forces are not correct
Moderators: Global Moderator, Moderator
WARNING: stress and forces are not correct
Last edited by Damien on Mon Jan 23, 2006 12:18 pm, edited 1 time in total.
-
- Administrator
- Posts: 2921
- Joined: Tue Aug 03, 2004 8:18 am
- License Nr.: 458
WARNING: stress and forces are not correct
It makes no sense to keep the charge density constant (ICHARG-11)
and relax the ions (ISIF=2, IBRION=1) at one time. Actually, as you set NSW=0,
the positions are not updated anyway, and hence you can ignore that warning.
In your case I would prepare 2 separate INCAR files,
1) for the ionic relaxations (ICHARG not set)
2) for the post-processing after the structure is relaxed (ICHARG=11, NSW=0, but IBRION and ISIF not set )
and relax the ions (ISIF=2, IBRION=1) at one time. Actually, as you set NSW=0,
the positions are not updated anyway, and hence you can ignore that warning.
In your case I would prepare 2 separate INCAR files,
1) for the ionic relaxations (ICHARG not set)
2) for the post-processing after the structure is relaxed (ICHARG=11, NSW=0, but IBRION and ISIF not set )
Last edited by admin on Thu Jan 26, 2006 2:53 pm, edited 1 time in total.