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Python

Packmol-grade molecular packing in Rust, with a first-class Python binding.

molpack arranges \(N\) molecule types under geometric restraints without overlaps. The engine is a faithful port of Packmol's GENCAN-driven algorithm (Martínez et al. 2009); five canonical workloads stay pinned against Packmol reference output.

At a glance

import molrs
from molpack import GencanPack, Target

frame = molrs.io.read_pdb("water.pdb")

water = (
    Target(frame, count=100)
    .with_name("water")
    .with_restraint(molrs.core.Cuboid([0.0, 0.0, 0.0], [40.0, 40.0, 40.0]))
)

packer = GencanPack().with_tolerance(2.0).with_seed(42)
result = packer.run([water], max_loops=200)
print(f"packed {result.frame['atoms'].n_rows} atoms")

Next steps

Installation pip install and verification. Quickstart First pack end-to-end. Targets Templates, counts, fixed placement. Restraints Geometric and collective restraints. Packer Builder options, diagnostics, callbacks. Chain growth Dense polymer melts via the CbmcGrow engine. Periodic boundaries PBC rules and validation. Examples Packmol-equivalent workloads. API reference Class-by-class summary.

See also