# How to run SSAGES on LAMMPS¶

Using SSAGES with LAMMPS is as simple as running LAMMPS by itself. SSAGES requires the same files and commands that a stand-alone LAMMPS simulation requires, with one exception. LAMMPS input files usually contain a ‘run’ command. Instead of a run command, SSAGES requires an extra ‘fix’ in the LAMMPS input file:

fix ssages all ssages


Additionally, SSAGES requires a .json file which specifies the method that will be used, collective variables, etc. The MD Engine should also be specified

"type": "LAMMPS"


The number of MD steps of the simulation are specified in “MDSteps” of the .json file. LAMMPS log files for each simulation are specified in the “logfile” of the .json file. If they are specified as “none”, no LAMMPS log files will be generated.

All values in the .json file will be in the units specified in the LAMMPS input file.