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<DIV><%--AID_SENDTO_BEGIN--%>GROMACS Mailing List<%--AID_SENDTO_END--%>
<DIV>hi users:</DIV>
<DIV> </DIV>
<DIV>what is a segmentation fault?</DIV>
<DIV>i think there must be some erros in the run parameters.</DIV>
<DIV>who can tell me the where and why? </DIV>
<DIV>i want to simulate the process to pull the dickerson DNA (i get it from
http:\\folding.stanford.edu\ffamber)<%--AID_SENDTO_BEGIN--%></DIV>
<DIV>there is my mdrun.mdp</DIV>
<DIV>; RUN CONTROL
PARAMETERS<BR>integrator
= md<BR>; Start time and timestep in
ps<BR>tinit
=
0<BR>dt
=
0.003<BR>nsteps
= 50000<BR>; For exact run continuation or redoing part of a
run<BR>init_step
= 0<BR>; mode for center of mass motion
removal<BR>comm-mode
= None<BR>; number of steps for center of mass motion
removal<BR>nstcomm
= 1<BR>; group(s) for center of mass motion
removal<BR>comm-grps
= </DIV>
<DIV>; LANGEVIN DYNAMICS OPTIONS<BR>; Temperature, friction coefficient (amu/ps)
and random
seed<BR>bd-temp
=
300<BR>bd-fric
=
0<BR>ld-seed
= 1993</DIV>
<DIV>; ENERGY MINIMIZATION OPTIONS<BR>; Force tolerance and initial
step-size<BR>emtol
=
10<BR>emstep
= 0.01<BR>; Max number of iterations in
relax_shells<BR>niter
= 20<BR>; Step size (1/ps^2) for minimization of flexible
constraints<BR>fcstep
= 0<BR>; Frequency of steepest descents steps when doing
CG<BR>nstcgsteep
=
1000<BR>nbfgscorr
= 10</DIV>
<DIV>; OUTPUT CONTROL OPTIONS<BR>; Output frequency for coords (x), velocities
(v) and forces
(f)<BR>nstxout
=
0<BR>nstvout
=
0<BR>nstfout
= 0<BR>; Checkpointing helps you continue after
crashes<BR>nstcheckpoint
= 1000<BR>; Output frequency for energies to log file and energy
file<BR>nstlog
=
100<BR>nstenergy
= 100<BR>; Output frequency and precision for xtc
file<BR>nstxtcout
=
100<BR>xtc-precision
= 1000<BR>; This selects the subset of atoms for the xtc file. You can<BR>;
select multiple groups. By default all atoms will be
written.<BR>xtc-grps
= Protein NA+<BR>; Selection of energy
groups<BR>energygrps
= Protein NA+ SOL</DIV>
<DIV>; NEIGHBORSEARCHING PARAMETERS<BR>; nblist update
frequency<BR>nstlist
= 10<BR>; ns algorithm (simple or
grid)<BR>ns_type
= grid<BR>; Periodic boundary conditions: xyz (default), no (vacuum)<BR>; or
full (infinite systems
only)<BR>pbc
= xyz<BR>; nblist cut-off
<BR>rlist
= 1.0<BR>domain-decomposition = no</DIV>
<DIV>; OPTIONS FOR ELECTROSTATICS AND VDW<BR>; Method for doing
electrostatics<BR>coulombtype
= PME<BR>rcoulomb-switch =
0<BR>rcoulomb
= 1.0<BR>; Dielectric constant (DC) for cut-off or DC of reaction
field<BR>epsilon-r
= 1<BR>; Method for doing Van der
Waals<BR>vdw-type
= Cut-off<BR>; cut-off lengths
<BR>rvdw-switch
=
0<BR>rvdw
= 1.0<BR>; Apply long range dispersion corrections for Energy and
Pressure<BR>DispCorr
= No<BR>; Extension of the potential lookup tables beyond the
cut-off<BR>table-extension
= 1<BR>; Spacing for the PME/PPPM FFT
grid<BR>fourierspacing
= 0.12<BR>; FFT grid size, when a value is 0 fourierspacing will be
used<BR>fourier_nx
=
0<BR>fourier_ny
=
0<BR>fourier_nz
= 0<BR>; EWALD/PME/PPPM
parameters<BR>pme_order
=
4<BR>ewald_rtol
=
1e-05<BR>ewald_geometry
= 3d<BR>epsilon_surface =
0<BR>optimize_fft
= no</DIV>
<DIV>tcoupl
= No</DIV>
<DIV>Pcoupl
= no</DIV>
<DIV>; OPTIONS FOR BONDS
<BR>constraints
= none<BR>; Type of constraint
algorithm<BR>constraint-algorithm = Lincs<BR>; Do not
constrain the start
configuration<BR>unconstrained-start = no<BR>; Use
successive overrelaxation to reduce the number of shake
iterations<BR>Shake-SOR
= no<BR>; Relative tolerance of
shake<BR>shake-tol
= 1e-04<BR>; Highest order in the expansion of the constraint coupling
matrix<BR>lincs-order
= 4<BR>; Number of iterations in the final step of LINCS. 1 is fine for<BR>;
normal simulations, but use 2 to conserve energy in NVE runs.<BR>; For energy
minimization with constraints it should be 4 to
8.<BR>lincs-iter
= 1<BR>; Lincs will write a warning to the stderr if in one step a bond<BR>;
rotates over more degrees
than<BR>lincs-warnangle =
30<BR>; Convert harmonic bonds to morse
potentials<BR>morse
= no</DIV>
<DIV>; Non-equilibrium MD
stuff<BR>acc-grps
=
<BR>accelerate
=
<BR>freezegrps
=
a_189_568<BR>freezedim
= Y Y Y<BR>cos-acceleration =
0</DIV>
<DIV><%--AID_EDIT_ATTACHMENT_BEGIN--%>thanks </DIV>
<DIV><A
href="mailto:<%--AID_FROMADDRESS_BEGIN--%>qi-wenpeng@mail.sdu.edu.cn<%--AID_FROMADDRESS_END--%>"><%--AID_FROMADDRESS_BEGIN--%>qi-wenpeng@mail.sdu.edu.cn<%--AID_FROMADDRESS_END--%></A></DIV>
<DIV>2005-8-14 </DIV></DIV></BODY></HTML>