openff-interchange documentation

Exporting to other software

GROMACS

Once an Interchange object has been constructed, the .gro and .top files can be written using Interchange.to_top() and Interchange.to_gro():

interchange.to_gro("out.gro")
interchange.to_top("out.top")

An .mdp file with settings inferred from data in the Interchange object can also be written. Note that this file will only run a single-point energy calculaqtion. nsteps and other lines should be modified to before running an MD simulation. This will write a file auto_generated.mdp:

from openff.interchange.drivers.gromacs import _write_mdp_file

_write_mdp_file(interchange)

LAMMPS

An Interchange object can be written to a LAMMPS data file with Interchange.to_lammps()

interchange.to_lammps("data.lmp")

An input file with settings inferred from data in the Interchange object can also be written. Note that this file will only run a single-point energy calculation. run and other commands should be modified to before running an MD simulation. This will write a file run.inp:

from openff.interchange.drivers.gromacs import _write_mdp_file

_write_lammps_input(interchange, "run.inp")

OpenMM

An Interchange object can be converted to an openmm.System object with Interchange.to_openmm().

openmm_sys = interchange.to_openmm()

By default, this will separate non-bonded interactions into several different openmm.Force objects. To combine everything into a single openmm.NonbondedForce, use the combine_nonbonded_forces=True argument.

Amber

Under construction!

CHARMM

Under construction!