[gmx-users] segmentation fault in md

[ISHRAT JAHAN]

Dear all
 I am trying to simulate 3M urea in a water box.when i do the mdrun of pr ,
i get too many LINCS warning and also segmentation fault(core dumped).

I am pasting my em.mdp and pr.mdp file below-
em.mdp
;
;    User spoel (236)
;    Wed Nov  3 17:12:44 1993
;    Input file
;
cpp                 =  /usr/bin/cpp
define              =  -DFLEX_SPC
constraints         = all-bonds
integrator          = steep
nsteps              =  2000
;
;    Energy minimizing stuff
;
emtol               =  100
emstep              =  0.01
nstcomm             =  1
ns_type             =  grid
rlist               =  0.15
coulombtype         = PME
rcoulomb            =  0.15
rvdw                = .19
fourierspacing = 0.12
fourier_nx = 0
fourier_ny = 0
fourier_nz = 0
pme_order = 4
ewald_rtol = 1e-5
optimize_fft = yes
Tcoupl              =  no
Pcoupl              =  no
gen_vel             =  no


pr.mdp

;
;    User spoel (236)
;    Wed Nov  3 17:12:44 1993
;    Input file
;
title               =  Yo
cpp                 =  /usr/bin/cpp
define              =  -DPOSRES
constraints         = all-bonds
constraintalgorithm =  LINCS
integrator          =  md
dt                  =  0.001    ; ps !
nsteps              =  10000    ; total 50 ps.
nstcomm             =  10
nstxout             =  500
nstvout             =  1000
nstfout             = 10
nstlog              =  10
nstenergy           =  10
nstlist             =  10
ns_type             =  grid
rlist               =  2
coulombtype         =  PME
rcoulomb            =  2
rvdw                =  2
fourierspacing = 0.12
fourier_nx = 0
fourier_ny = 0
fourier_nz = 0
pme_order = 4
ewald_rtol = 1e-5
optimize_fft = yes
; Berendsen temperature coupling is on in two groups
Tcoupl              =  V-rescale
tc-grps            =  URE   Water
tau_t               =  0.1    0.1
ref_t               =  300    300
; Energy monitoring
energygrps        =  URE Water
; Pressure coupling is on
Pcoupl              =  Berendsen
tau_p               =  0.5
compressibility     =  4.5e-5
ref_p               =  1.0
; Generate velocites is on at 300 K.
gen_vel             =  yes
gen_temp            =  300.0
gen_seed            =  173529

thanks in advance