What is wrong with my dynamic matrix calculation?

[jianmin]

Hi guys and especially Prof. Graeme,
Recently I tried to run a dynamic matrix calculation for the gas phase H2O molecule in a 15x15x15 Angstroms^3 box to get its vibrational frequencies. The INCAR parameters are:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ENCUT = 400.0 eV # energy cut-off for the calculation
PREC = Accurate # Normal precision
LREAL = Auto # real space projection .FALSE. or Auto

EDIFF = 1E-7 # threshold for SCF convergence
IBRION = 2 # CG algorithm
ISIF = 2 # forces and stress are optimized

ISMEAR = 0
SIGMA = 0.05

# frequency calculations
NSW = 10
ICHAIN = 1
POTIM = 0.0

# output controls
LCHARG = .FALSE.
LWAVE = .FALSE.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The job stopped after 1 ionic step. Did I miss some parameter(s) in the INCAR file? Look forward to solutions for this one. Thanks.

[graeme]

Try setting EDIFFG to a very small value (e.g. EDIFFG = -1e-8).