Install¶

molpack ships in three forms — the CLI binary, the Rust crate, and the Python binding. Pick the surface that matches your workflow.

CLI¶

For Packmol-style .inp scripts:

cargo install molcrafts-molpack --features cli
molpack --help

Rust crate¶

For programmatic use from Rust code:

cargo add molcrafts-molpack

Add the cli feature in your workspace if you also want the binary in-tree.

Python binding¶

For notebooks and pipelines:

pip install molcrafts-molpack molcrafts-molrs

molcrafts-molrs provides molrs.Frame plus PDB / XYZ readers — the Python wheel itself is I/O-free and relies on your installed molcrafts-molrs for all frame loading. Python 3.12 or newer is required.

import molpack
print(molpack.Molpack)

Pre-built wheels are published for CPython 3.13 on Linux (manylinux x86-64) and macOS (a single universal2 wheel covering Apple Silicon and Intel). On any other platform or Python version — Windows, Linux aarch64, or a different interpreter — pip falls back to the published source distribution and builds the wheel locally, which needs a Rust toolchain.

Build from source¶

When you are modifying the crate or Python binding:

git clone https://github.com/MolCrafts/molpack
cd molpack

# Rust library + CLI binary
cargo build
cargo build --features cli --bin molpack

# Python binding
cd python
pip install maturin
maturin develop --release

The Python package builds against the local Rust crate under ../, so this is the right path for contributor workflows.

Next steps¶

After verifying the install, run a first pack from Getting Started.