[gmx-users] pulling of molecule in GROMACS 4.03

anirban polley polley.anirban at gmail.com
Wed Mar 25 12:11:12 CET 2009


Dear Sir,
             I want to pull a molecule called PRO from the lipid membrane
DPP. To do this I have written the .mdp file as following from the help of
gromacs mannual 4.0 . But when I try to make .tpr file from the .gro file,
it says that "segmentation fault".
             Can you please write the correct .mdp file for the pulling? It
will be really a great help to me.
Thanking you,
Anirban

             ;
;       File 'mdout.mdp' was generated
;       By user: psn (17109)
;       On host: p690k
;       At date: Fri Jul 23 12:43:31 2004
;

; VARIOUS PREPROCESSING OPTIONS =
title                    = lipid bilayer in water
cpp                      = /lib/cpp
include                  =
define                   =

; RUN CONTROL PARAMETERS =
integrator               = md
; start time and timestep in ps =
tinit                    = 500
dt                       = 0.002
nsteps                   = 1750000
; mode for center of mass motion removal =
comm-mode                = Linear
; number of steps for center of mass motion removal =
nstcomm                  = 1
; group(s) for center of mass motion removal =
comm-grps                =

; LANGEVIN DYNAMICS OPTIONS =
; Temperature, friction coefficient (amu/ps) and random seed =
;bd-temp                  = 300
;I have commute the above line as it has no exitance
bd-fric                  = 0
ld-seed                  = 1993

; ENERGY MINIMIZATION OPTIONS =
; Force tolerance and initial step-size =
emtol                    = 100
emstep                   = 0.01
; Max number of iterations in relax_shells =
niter                    = 20
; Step size (1/ps^2) for minimization of flexible constraints =
fcstep                   = 0
; Frequency of steepest descents steps when doing CG =
nstcgsteep               = 1000

; OUTPUT CONTROL OPTIONS =
; Output frequency for coords (x), velocities (v) and forces (f) =
nstxout                  = 5000
nstvout                  = 5000
nstfout                  = 0
; Output frequency for energies to log file and energy file =
nstlog                   = 250
nstenergy                = 250
; Output frequency and precision for xtc file =
nstxtcout                = 0
xtc-precision            = 1000
; This selects the subset of atoms for the xtc file. You can =
; select multiple groups. By default all atoms will be written. =
xtc-grps                 =
; Selection of energy groups =
energygrps               =

; NEIGHBORSEARCHING PARAMETERS =
; nblist update frequency =
nstlist                  = 10
; ns algorithm (simple or grid) =
ns_type                  = grid
; Periodic boundary conditions: xyz or no =
pbc                      = xyz
; nblist cut-off         =
rlist                    = 1.0
domain-decomposition     = no

; OPTIONS FOR ELECTROSTATICS AND VDW =
; Method for doing electrostatics =
coulombtype              = PME      ;Reaction-Field
rcoulomb-switch          = 0
rcoulomb                 = 1.0      ;2.0
; Dielectric constant (DC) for cut-off or DC of reaction field =
epsilon_r                = 80.0
epsilon_rf               = 1
;I have done some thing new according to mannual and warnings and error
; Method for doing Van der Waals =
vdwtype                  = Cut-off
; cut-off lengths        =
rvdw-switch              = 0
rvdw                     = 1.0
; Apply long range dispersion corrections for Energy and Pressure =
DispCorr                 = No
; Spacing for the PME/PPPM FFT grid =
fourierspacing           = 0.12
; FFT grid size, when a value is 0 fourierspacing will be used =
fourier_nx               = 0
fourier_ny               = 0
fourier_nz               = 0
; EWALD/PME/PPPM parameters =
pme_order                = 4
ewald_rtol               = 1e-05
ewald_geometry           = 3d
epsilon_surface          = 0
optimize_fft             = yes

; OPTIONS FOR WEAK COUPLING ALGORITHMS =
; Temperature coupling   =
Tcoupl                   = berendsen
; Groups to couple separately =
tc-grps                  = DPP  SOL PRO
; Time constant (ps) and reference temperature (K) =
tau_t                    = 0.1   0.1   0.1
ref_t                    = 310   310   310
; Pressure coupling      =
Pcoupl                   = berendsen
Pcoupltype               = semiisotropic
; Time constant (ps), compressibility (1/bar) and reference P (bar) =
tau_p                    = 1.0    1.0
compressibility          = 4.5e-5 4.5e-5
ref_p                    = 1.0    1.0

; SIMULATED ANNEALING CONTROL =
annealing                = no
; Time at which temperature should be zero (ps) =
;zero-temp_time           = 0
;I have commute the above line as it has no exitance

; GENERATE VELOCITIES FOR STARTUP RUN =
gen_vel                  = yes
gen_temp                 = 310.0
gen_seed                 = 173529

; OPTIONS FOR BONDS     =
constraints              = all-bonds
; Type of constraint algorithm =
constraint_algorithm     = lincs
; Do not constrain the start configuration =
continuation             = yes
;unconstrained-start      = no
; Use successive overrelaxation to reduce the number of shake iterations =
Shake-SOR                = no
; Relative tolerance of shake =
shake-tol                = 0.0001
; Highest order in the expansion of the constraint coupling matrix =
lincs_order              = 4
; Lincs will write a warning to the stderr if in one step a bond =
; rotates over more degrees than =
lincs-warnangle          = 30
; Convert harmonic bonds to morse potentials =
morse                    = no



;COM pulling
pull                     = umbrella
pull_geometry            = cylinder
pull_dim                 = N N Y
pull_r1                  = 1
pull_r0                  = 1
;pull_constr_tot          = 1e-6
pull_start               = yes
pull_nstxout             = 10
pull_nstfout             = 1
pull_ngroups             = 1
;name of reference group
pull_group0              = DPP
;pull_weights             = 0
;name of pull group
pull_group1              = PIP
;pull_weights             = 0
pull_vec1                = 0.0 0.0 -1
;ref. distance at t=0
pull_init1               =
;rate of change of ref. gr. [nm/ps]
pull_rate1               = 0.0005
;force constant [KJ mol^-1 nm^-2]
pull_k1                  = 500
;pull_kB1                =



; ENERGY GROUP EXCLUSIONS =
; Pairs of energy groups for which all non-bonded interactions are excluded
=
energygrp_excl           =

; NMR refinement stuff  =
; Distance restraints type: No, Simple or Ensemble =
disre                    = No
; Force weighting of pairs in one distance restraint: Conservative or Equal
=
disre-weighting          = Conservative
; Use sqrt of the time averaged times the instantaneous violation =
disre-mixed              = no
disre-fc                 = 1000
disre-tau                = 0
; Output frequency for pair distances to energy file =
nstdisreout              = 100
; Orientation restraints: No or Yes =
orire                    = no
; Orientation restraints force constant and tau for time averaging =
orire-fc                 = 0
orire-tau                = 0
orire-fitgrp             =
; Output frequency for trace(SD) to energy file =
nstorireout              = 100

; Free energy control stuff =
free-energy              = no
init-lambda              = 0
delta-lambda             = 0
sc-alpha                 = 0
sc-sigma                 = 0.3

; Non-equilibrium MD stuff =
acc-grps                 =
accelerate               =
freezegrps               =
freezedim                =
cos-acceleration         = 0

; Electric fields       =
; Format is number of terms (int) and for all terms an amplitude (real) =
; and a phase angle (real) =
E-x                      =
E-xt                     =
E-y                      =
E-yt                     =
E-z                      =
E-zt                     =

; User defined thingies =
user1-grps               =
user2-grps               =
userint1                 = 0
userint2                 = 0
userint3                 = 0
userint4                 = 0
userreal1                = 0
userreal2                = 0
userreal3                = 0
userreal4                = 0
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