I am getting a Segmentation fault when trying to run an NVT on an epoxy graphite system. I have had a few fellow students look at my input data and nobody knows why I am getting this. Also, there is very little explanation on this error. Would you please take a look at my input file and see if you can tell why I am getting this fault?
# NVT file for epoxy graphite system VDW set at 1% for minimization
units real
dimension 3
boundary p p f
atom_style molecular
neighbor 5.0 bin
neigh_modify every 10 delay 20 one 4000 page 250000
it is near impossible to debug this without a full input
(including the data file).
most likely the error is in the initial coordinates and
you have an overflow of some sorts.
if you get a segmentation fault, you can always force
a core dump and then generate a stack trace to find
out in which subroutine the executable craters.
I am trying to apply the FENE force field for my current simulations. I have looked into literature to help define the parameters needed for this force field. Where can I find the sigma and epsilon values for the FENE force field? Are these the same as the LJ sigma and epsilon values? Also, is there a predefined cut-off distance R_0, or do people just experiment with arbitrary values? How exactly does lammps use these parameters when running a simulation?
Any help on the subject of the FENE force field would be extremely helpful!
The formula for FENE is on the bond_style fene doc page,
so that's what LAMMPS computes. Look for papers by G Grest
on how to use it for polymer models. See bench/in.chain for typical bead/spring
polymer chain FENE params.
i. e. 1.0 1.0 30 1.5 if you use units where sigma_{LJ} = epsilon_{LJ} = 1.0. If you’re not using the K-G bead spring model, best thing to do is play with plotting the potential for different k and R_0 to get a feel for the implications of varying them for your model.