[lammps-users] Input files for LAMMPS

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1

Hello,

I am Syamal Tallury. I am new to LAMMPS. I do MD simulations with CNTs and polymers.
I am unable to build the input files for LAMMPS. I have tried the charmm2lmp.pl but I need to use the COMPASS force field for my simulations.

Please help me with some information on how to build the input files for LAMMPS to use COMPASS force field.

Thank you.
Syamal Tallury.
NCSU.

2

Hello,

I am Syamal Tallury. I am new to LAMMPS. I do MD
simulations with CNTs and polymers.
I am unable to build the input files for LAMMPS. I
have tried the charmm2lmp.pl but I need to use the COMPASS force field for my
simulations.

Please help me with some information on how to
build the input files for LAMMPS to use COMPASS force field.

you first have to implement (=program) the require functional
forms for the various forcefield terms that are not present
in LAMMPS currently. please read up on the definition of COMPASS
and compare it to the LAMMPS documentation.

axel.

3

I have had no problems using COMPASS with LAMMPS. I think all
of the forcefield terms are present in the class2 package,
unless for some reason LAMMPS lost that functionality in the
latest release.

The difficulty, Syamal, is that you do need to write code to
build your own input file or modify the output from some other
package in which you are defining the positions and
connectivity for your systems. It's not too bad to type in all
the forcefield parameters by hand, but you definitely want to
write a code that does the connectivity and positions for your
system.

Joanne Budzien

4

I have had no problems using COMPASS with LAMMPS. I think all
of the forcefield terms are present in the class2 package,
unless for some reason LAMMPS lost that functionality in the
latest release.

no. that was my mistake. not enough coffee, i guess.
i just got a refill and will go back to coding....

thanks for correcting me.

cheers,
   axel.

5

See the msi2lmp tool in the tools dir.

Steve