The Error in the relaxatioion of atom positions

[okuno]

Dear Vasp Users.

I'm working the relaxation of the 40 atomic system.
In the process of relaxation, the calculation stopped with the
error message like below,

DAV: 8 -0.308711193018E+03 0.47294E-09 0.89095E-10 1308 0.280E-06
35 F= -.30871119E+03 E0= -.30871119E+03 d E =0.453615E-05
curvature: 0.00 expect dE= 0.000E+00 dE for cont linesearch 0.000E+00
ZBRENT: fatal internal in brackting
system-shutdown; contact gK immediately

Is it the failure of conjugate gradient method? What is the treatment
of this error?

My INCAR file and POSCAR file is below,

SYSTEM = PZT_Tetra_Zr_Center

Startparameter for this Run:
NWRITE = 2; LPETIM=F write-flag & timer
#ISTART = 1 job : 0-new 1-cont 2-samecut
#ICHARG = 1 initial charge 0-calc 1-from CHGCAR, 2-super potision


Electronic minimization
ALGO = NORMAL # default for IALGO=38
IALGO = 38 # default Davodason block iteration scheme
EDIFF = 1.0E-05 # stopping -criterion for ELM


relaxation
IBRION = 2
ISFI = 2
NSW=100
NELMIN=8
EDIFFG = -0.001

LREAL=Auto

NELM =100 # maximum electronic SC steps (default=60)

GGA = 91 # GGA PB PW LM 91 PE RP

ISMEAR = -5
SIGMA = 0.1

#POSCAR
P4mm_40atom
1.00000000000000
8.0191066511799995 0.0000000000000000 0.0000000000000000
0.0000000000000000 8.0191066511799995 0.0000000000000000
0.0000000000000000 0.0000000000000000 8.3799664504799996
8 4 4 24
Selective dynamics
Direct
0.2500000000000000 0.2500000000000000 0.2494943422543176 F F T
0.2500000000000000 0.7500000000000000 0.2494943422543176 F F T
0.7500000000000000 0.2500000000000000 0.2494943422543176 F F T
0.7500000000000000 0.7500000000000000 0.2494943422543176 F F T
0.2500000000000000 0.2500000000000000 0.7813008607977519 F F T
0.2500000000000000 0.7500000000000000 0.7813008607977519 F F T
0.7500000000000000 0.2500000000000000 0.7813008607977519 F F T
0.7500000000000000 0.7500000000000000 0.7813008607977519 F F T
0.0000000000000000 0.0000000000000000 0.4946785505877939 F F T
0.0000000000000000 0.5000000000000000 0.4946785505877939 F F T
0.5000000000000000 0.0000000000000000 0.4946785505877939 F F T
0.5000000000000000 0.5000000000000000 0.4946785505877939 F F T
0.0000000000000000 0.0000000000000000 0.9914852576005875 F F T
0.0000000000000000 0.5000000000000000 0.9914852576005875 F F T
0.5000000000000000 0.0000000000000000 0.9914852576005875 F F T
0.5000000000000000 0.5000000000000000 0.9914852576005875 F F T
0.2500000000000000 0.0000000000000000 0.9633672423254386 F F T
0.2500000000000000 0.5000000000000000 0.9633672423254386 F F T
0.7500000000000000 0.0000000000000000 0.9633672423254386 F F T
0.7500000000000000 0.5000000000000000 0.9633672423254386 F F T
0.0000000000000000 0.2500000000000000 0.9633672423254386 F F T
0.0000000000000000 0.7500000000000000 0.9633672423254386 F F T
0.5000000000000000 0.2500000000000000 0.9633672423254386 F F T
0.5000000000000000 0.7500000000000000 0.9633672423254386 F F T
0.2500000000000000 0.0000000000000000 0.4389112312337884 F F T
0.2500000000000000 0.5000000000000000 0.4389112312337884 F F T
0.7500000000000000 0.0000000000000000 0.4389112312337884 F F T
0.7500000000000000 0.5000000000000000 0.4389112312337884 F F T
0.0000000000000000 0.2500000000000000 0.4389112312337884 F F T
0.0000000000000000 0.7500000000000000 0.4389112312337884 F F T
0.5000000000000000 0.2500000000000000 0.4389112312337884 F F T
0.5000000000000000 0.7500000000000000 0.4389112312337884 F F T
0.0000000000000000 0.0000000000000000 0.2042040280143551 F F T
0.0000000000000000 0.5000000000000000 0.2042040280143551 F F T
0.5000000000000000 0.0000000000000000 0.2042040280143551 F F T
0.5000000000000000 0.5000000000000000 0.2042040280143551 F F T
0.0000000000000000 0.0000000000000000 0.7319300135837434 F F T
0.0000000000000000 0.5000000000000000 0.7319300135837434 F F T
0.5000000000000000 0.0000000000000000 0.7319300135837434 F F T
0.5000000000000000 0.5000000000000000 0.7319300135837434 F F T

[admin]

most probably, your system is converged to within the numerical accuracy (please have a look at the forces in OUTCAR), especially if the potential hypersurface is very flat around that minimum.
-- Usually it is sufficient to set EDIFFG=-0.01
-- you may try to increase PREC