calculation of energy barrier

[danghongli]

Hello everyone,

I used VASP for the calculation of energy barrier, my INCAR is:
System = Elastic Band Method
LSCALAPACK = .FALSE.
IBRION = 3
POTIM = 0.003
ISYM = 0
ICHAIN = 2
IMAGES = 2
SPRING = -5
NPAR = 1

ISMEAR = 0
ENCUT = 348.097
!LREAL = .FALSE.
GGA = 91
!POTIM = 0.05
NSW = 180
!IBRION = 2
ISPIND = 2
ISPIN = 2
!NBANDS= 55

but there are something wrong when i excute the program, and the err report is:
In DLOG(dx) or LOG(dx) or DLOG10(dx) or LOG10(dx) or DLOG2(dx) or LOG2(dx), dx.le.0.0 (dx=nan ).
In DLOG(dx) or LOG(dx) or DLOG10(dx) or LOG10(dx) or DLOG2(dx) or LOG2(dx), dx.le.0.0 (dx=nan ).
In DLOG(dx) or LOG(dx) or DLOG10(dx) or LOG10(dx) or DLOG2(dx) or LOG2(dx), dx.le.0.0 (dx=nan ).
In DLOG(dx) or LOG(dx) or DLOG10(dx) or LOG10(dx) or DLOG2(dx) or LOG2(dx), dx.le.0.0 (dx=nan ).
Error occurs at or near line 1215 of expw_
Called from or near line 1111 of fun_
Called from or near line 1084 of ggaxcs_
Called from or near line 962 of ggaspin_
Called from or near line 282 of fexcgs__
Called from or near line 84 of fexcgs_
Called from or near line 135 of pot.potlok_
Called from or near line 260 of elmin_
Called from or near line 2295 of MAIN__
Error occurs at or near line 1215 of expw_
Called from or near line 1111 of fun_
Called from or near line 1084 of ggaxcs_
Called from or near line 962 of ggaspin_
Called from or near line 282 of fexcgs__
Called from or near line 84 of fexcgs_
Called from or near line 135 of pot.potlok_
Called from or near line 260 of elmin_
Called from or near line 2295 of MAIN__
Error occurs at or near line 1215 of expw_
Called from or near line 1111 of fun_
Called from or near line 1084 of ggaxcs_
Called from or near line 962 of ggaspin_
Called from or near line 282 of fexcgs__
Called from or near line 84 of fexcgs_
Called from or near line 135 of pot.potlok_
Called from or near line 260 of elmin_
Called from or near line 2295 of MAIN__
Error occurs at or near line 1215 of expw_
Called from or near line 1111 of fun_
Called from or near line 1084 of ggaxcs_
Called from or near line 962 of ggaspin_
Called from or near line 282 of fexcgs__
Called from or near line 84 of fexcgs_
Called from or near line 135 of pot.potlok_
Called from or near line 260 of elmin_
Called from or near line 2295 of MAIN__

I don't know what it is, can you have me with this?
Thanks in advance

[admin]

strange, for any well-behaved calculation, dx should never become zero in function expw, it is computed from quantities that should all be positive.
please
1) check if the geometry input of this run was reasonable (in order to give reasonable charge densities) : please have a look at the interpolated input geometries of your images and the NN distances of the atoms corresponding to these POSCARs. If necessary, reduce POTIM and/or change the ionic relaxation algorithm
2) recompile vasp with lowest optimization for xcgrad and xcspin (if this is not included in your makefile anyway)