There is a puzzling problem in applying esternal field

[yjwang]

Is there any solution for "LAPACK: Routine ZPOTRF failed 1" when applying esternal electrostatic field in slab. My simulation died after relax one Ionic step. Any suggestion will be highly appreciated. As shown below:
1 F= -.11576990E+05 E0= -.11576981E+05 d E =-.115770E+05
BRION: g(F)= 0.499E+04 g(S)= 0.743E+09
bond charge predicted
LAPACK: Routine ZPOTRF failed! 1
LAPACK: Routine ZPOTRF failed! 1
LAPACK: Routine ZPOTRF failed! 1
LAPACK: Routine ZPOTRF failed! 1
LAPACK: Routine ZPOTRF failed! 1
LAPACK: Routine ZPOTRF failed! 1
LAPACK: Routine ZPOTRF failed! 1
LAPACK: Routine ZPOTRF failed! 1
LAPACK: Routine ZPOTRF failed! 1
LAPACK: Routine ZPOTRF failed! 1
LAPACK: Routine ZPOTRF failed! 1
LAPACK: Routine ZPOTRF failed! 1
LAPACK: Routine ZPOTRF failed! 1
LAPACK: Routine ZPOTRF failed! 1
LAPACK: Routine ZPOTRF failed! 1
LAPACK: Routine ZPOTRF failed! 1
LAPACK: Routine ZPOTRF failed! 1
LAPACK: Routine ZPOTRF failed! 1
LAPACK: Routine ZPOTRF failed! 1
LAPACK: Routine ZPOTRF failed! 1
LAPACK: Routine ZPOTRF failed! 1
LAPACK: Routine ZPOTRF failed! 1
LAPACK: Routine ZPOTRF failed! 1
LAPACK: Routine ZPOTRF failed! 1
LAPACK: Routine ZPOTRF failed! 1
LAPACK: Routine ZPOTRF failed! 1
LAPACK: Routine ZPOTRF failed! 1
LAPACK: Routine ZPOTRF failed! 1
LAPACK: Routine ZPOTRF failed! 1
LAPACK: Routine ZPOTRF failed! 1
LAPACK: Routine ZPOTRF failed! 1
LAPACK: Routine ZPOTRF failed! 1
Here is my INCAR param:
# Start parameter for this run:
SYSTEM = PTO-STO supercell
# Electronic Relaxation 1
PREC = M # precision : medium, high low
ENCUT = 450
NELM = 60 # maximal ELM
EDIFF = 1E-02 # stopping-criterion for ELM
NELMDL = -5 # No. of inconsistent ELM
NELMIN = 4 # minimal ELM

# Ionic relaxation
EDIFFG = -0.03 # stopping-criterion for IOM
NSW = 400 # number of steps for IOM
IBRION = 1 # ionic relax: 0-MD 1-quasi-New 2-CG
# NFREE = 10 # No. of ionic steps kept in the iteration history
ISIF = 3 # stress and delaxation
POTIM = 0.5 # time step in MD and scaling constant in relax
ISYM = 0 # symmetry : 0-no 1,2-yes

# DOS related values:
# ISMEAR = 0 # smearing method : -5-tet -1-fermi 0-gaus 1-MP
# SIGMA = 0.1

# Electric Field parameters:
EFIELD = 0.005
LDIPOL = .TRUE.
IDIPOL = 3

# Electronic relaxation 2 (details)
ALGO = Normal # algorithm
LREAL = .FALSE. # space where projection will be done

# NBANDS = 550

# NWRITE = 3
# IMIX = 1
AMIX = 0.2
BMIX = 0.0001
AMIX_MAG = 0.8
BMIX_MAG = 0.0001
LMAXMIX = 4

# Write Flag
LWAVE = .FALSE.
LCHARG = .FALSE.

[admin]

LAPACK error often appears because of mistakes in input.
E.g. when two atoms have identical coordinates.

[yjwang]

LAPACK error often appears because of mistakes in input.
E.g. when two atoms have identical coordinates.

So could you give me some good suggestions and solutions for input parameters, such as Mixing-tag ? Thank you.