Skip to content

LAMMPS Backmapping Package

Time-dependent backmapping (reverse mapping) from coarse-grained to atomistic resolution, implemented as a LAMMPS user package.

The method ramps a per-atom resolution parameter λ from 0 (pure CG) to 1 (pure AT) uniformly across the simulation box, gradually restoring atomistic detail while maintaining thermodynamic consistency.

References

Krajniak et al., "Generic Adaptive Resolution Method for Reverse Mapping of Polymers from Coarse-Grained to Atomistic Descriptions", J. Chem. Theory Comput. 2016, 12, 5549--5562. DOI: 10.1021/acs.jctc.6b00595

Krajniak, Zhang et al., "Reverse Mapping Method for Complex Polymer Systems", J. Comput. Chem. 2018. DOI: 10.1002/jcc.25129

Features

  • Smooth resolution transition -- lambda ramp with configurable rate drives CG → AT conversion over the course of the simulation
  • Lambda-weighted interactions -- pair, bond, and angle styles that automatically weight forces by the current resolution
  • CG force distribution -- CG-level forces are redistributed to AT atoms proportional to mass
  • Automated input generation -- the backmap-prep CLI reads a YAML settings file and produces LAMMPS data files, input scripts, and interaction tables from GROMACS topologies
  • Restart support -- per-atom lambda values are saved and restored across LAMMPS restarts

Components

Component Description
fix backmap Lambda ramp, CG-AT mapping, COM tracking, CG force distribution
pair_style backmap Lambda-weighted non-bonded pair forces
bond_style backmap/harmonic Lambda-weighted harmonic bond forces
bond_style backmap/table Lambda-weighted tabulated bond forces
angle_style backmap/harmonic Lambda-weighted harmonic angle forces
backmap-prep Python CLI for generating LAMMPS input files

License

GPL-3.0-or-later