nvt simulation is stable - getting error in gcmc

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1

Dear lammps users and experts,

I try to perform a gcmc simulation using 28jun14 version of lammps. When I run gcmc simulation simulation using fixgcmc command,

I get the “segmentation fault error”. As this is due to error in the input structure or may be due to blow up system, atoms crossing boundaries. I verified the input structure and run an nvt simulation for 1ns [to find error in input structure] . The structure from nvt simulation is quite stable. I get this error when i run gcmc simulations. The input file used is for gcmc simulation is as follows,

units real
atom_style full
bond_style harmonic
angle_style harmonic
pair_style lj/charmm/coul/charmm 8 9
pair_modify mix geometric
special_bonds lj/coul 0.0 0.0 1.0
boundary p p p
read_data test_org.data
neighbor 4.0 bin
neigh_modify every 2 delay 0 check yes page 100000
dielectric 1.0
thermo_style custom evdwl ecoul epair emol elong etail ebond pe ke etail
thermo 1
compute_modify thermo_temp dynamic yes
minimize 1.0e-4 1.0e-6 100 5000
min_style cg
timestep 1.0
molecule 10 co2.txt
group co2 molecule 10
fix 2 all nvt temp 298.0 298.0 100.0
fix 3 co2 gcmc 1 10 10 0 123456 298 -0.5 0.1 mol 10 pressure 0.15
thermo_style multi
thermo_modify lost ignore
dump 1 all xyz 1 test-gcmc-*.xyz

I try to decrease the time step and decreasing the damping coefficient also did not stabilized the system. Please help me to understand and rectify this error. I will greatly appreciate your help.

Thanks & Regards,

K. Mohan

2

Dear lammps users and experts,
                                                     I try to perform a gcmc
simulation using 28jun14 version of lammps. When I run gcmc simulation

when encountering a problem, always also try the very latest
patchlevel of LAMMPS.
bugfixes are published immediately and you can see which issues are
resolved here: LAMMPS Molecular Dynamics Simulator

simulation using fixgcmc command,
I get the "segmentation fault error". As this is due to error in the input
structure or may be due to blow up system, atoms crossing boundaries. I
verified the input structure and run an nvt simulation for 1ns [to find
error in input structure] . The structure from nvt simulation is quite
stable. I get this error when i run gcmc simulations. The input file used
is for gcmc simulation is as follows,

if you want somebody to seriously look into this, you have to provide
a full input.
please note, that inputs using "thermo_modify lost ignore" in regular
simulations is often hiding problems and thus will taint your claim
that your regular simulation is working correctly.

axel.

3

Paul may be able to comment on the GCMC Qs.
But Axel is correct, a simple input that illustrates
the issue is needed.

Steve

4

Hello sir,

Thank you very much for a reply. I have obtained a new patch for fix_gcmc from GIT and it’s running fine now.

Thanks & Regards,

K. Mohan Maruthi

5

Yes, I agree with Axel’s and Steve’s comments. If you’re still having problems with GCMC and send me complete input and data files, I can take a look.

Paul