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NEB problem

Posted: Tue Sep 23, 2008 10:50 am
by whzhang
I have complied VASP on (Intel(R) Xeon(R) CPU E5430 @ 2.66GHz )machine with openMPI 1.2.6. It works well except NEB calculations.

When I performed NEB calculations, the program stopped at the end of the first inoic step. That means I got the energy of each images of the first step. Mpirun is still running but without VASP processes.....

I am looking forward for your help.

Thanks a lot

NEB problem

Posted: Wed Sep 24, 2008 1:26 pm
by admin
strange, I have never heard of this problem before. Is there any useful information what has happened written in the job.stdout or the paralellization output files?
just to check:
please have a look
1) to which number IBRION and NSW are set in OUTCA
2) whether the forces of the OUTCARs in each image have reached the convergence limit (i.e., the job is really finished after just one step)

NEB problem

Posted: Wed Sep 24, 2008 7:34 pm
by whzhang
SYSTEM =HH-2*4

LREAL = .TURE.
PREC = Medium

ENCUT = 450 ev
NELM = 80
NELMIN = 5
NELMDL= -8
EDIFF = 1E-04
EDIFFG = -0.1
ISPIN = 2
INIMIX = 0
AMIX = 0.05
BMIX = 0.0001 ! almost zero, but 0 will crash some versions
AMIX_MAG = 0.2
BMIX_MAG = 0.0001 ! almost zero, but 0 will crash some versions

NSW=5000
IBRION=1
IMAGES = 4
ICHAIN = 0
LCLIMB = .TRUE.
SPRING = -5
POTIM=0.1


VOSKOWN = 1
LDIPOL = .TRUE.
IDIPOL = 3

ISIF = 2

ISMEAR = 0
SIGMA = 0.05

IALGO = 38
LWAVE = .FALSE.
LCHARG = .FALSE.

1)above is my input file and I check the two parameters in OUTCAR, they are the same with the input file.

2)yes, each image have reached the convergence. I got the summary (such as 1 F= -.25261730E+03 E0= -.25258336E+03 d E =-.252617E+03 mag= 28.4273) for each image. And the end of each OUTCAR is " NEB: forces: par spring, perp REAL, dneb 0.033455 6.854896 0.000000
NEB: distance to prev, next image, angle between 0.522892 0.529583 166.982703
NEB: projections on to tangent (spring, REAL) 0.033455 -2.933298

FORCES: max atom, RMS 5.087860 1.057746
FORCE total and by dimension 6.854978 4.828934
Quasi-Newton relaxation of ions (Broydens 2nd method)
g(Force) = 0.101E+01 g(Stress)= 0.000E+00
"

yes..this problem is very strange.....