lindhard

A clean-room, MIT-licensed Rust engine for Monte Carlo transport of ions and electrons in matter. It computes implantation range profiles, damage, sputtering and backscatter for ions, and energy deposition for low-energy electrons. SRIM/TRIM covers the same problem class; lindhard uses none of its code or data.

Status: early, pre-release (0.0.1). The amorphous ion core (milestone M0) is the most mature part, with the electron engine (M1), crystalline targets (M2) and dynamic composition and geometry (M3) under active development. Milestones and their state are tracked in WORK_PLAN.md, the design in docs/architecture.md. Known deviations from published data and from other codes are reported, not hidden, in docs/validation.md.

Quick start

cargo run -p lindhard-cli -- check examples/b_5keV_si.toml
cargo run --release -p lindhard-cli -- run examples/b_5keV_si.toml --out out/b_5keV_si

run writes summary.json and CSV profiles into the output directory. The input schema and output layout are in docs/cli.md; more inputs are in examples/.

Why another code

Some open codes already handle parts of this problem well. The gaps are in license and scope:

• SRIM/TRIM is closed source, Windows-only and non-commercial. It treats every target as amorphous and as fixed, so the target never changes with dose.
• Crystalline implant simulation is not available in any open, maintained code. That covers channeling under tilt and twist, screen oxides, and damage that builds up to amorphization. Today it means IMSIL, Crystal-TRIM, MARLOWE or commercial TCAD.
• Ion codes that are open are either copyleft (RustBCA, iradina, IM3D) or use stopping tables taken from SRIM (OpenTRIM).
• Low-energy electron transport (eV–50 keV, for e-beam lithography proximity functions, SEM and EBIC) has one permissive open code, Nebula, and it has stalled. The reference physics lives inside Geant4 or AGPL codes.

lindhard aims to be permissive, embeddable, fast, reproducible and validated:

• MIT license, with no copyleft dependency anywhere in the build.
• A library first; the CLI and the Python bindings sit on top of it (WASM later).
• Every ion runs on its own seeded random stream, so results do not depend on the thread count.
• Every model is checked against analytic limits, independent codes and published measurements (docs/validation.md).

docs/prior-art.md is the survey this project starts from. docs/history.md traces the method back to the 1947 Los Alamos neutron histories.

The name honours Jens Lindhard. His LSS theory is the standard theory of ion range, he did the foundational work on channeling, and his dielectric function is the starting point for inelastic electron scattering. Between them those cover both halves of this project.

Layout

Path	What
lindhard/	The library: materials, potentials, stopping, transport, tallies
lindhard-cli/	lindhard binary: TOML in, JSON/CSV out
lindhard-py/	lindhard Python package (pyo3 + maturin): NumPy arrays out, same TOML schema
examples/	Example CLI inputs
book/	Source of the lindhard book (physics manual and user guide), built with mdBook
tools/	Developer tools: profiling helpers
validation/	Validation harness: oracle runner, experimental datasets, results
docs/	Design, physics and project documentation (index below)

Documentation

• The lindhard book (source in book/): the physics manual, one page per model, and the user guide, including a first run from start to finish.
• docs/architecture.md: design and module plan.
• docs/cli.md: the lindhard command, input schema and outputs.
• docs/stopping-models.md: electronic stopping models, their validity ranges and sources.
• docs/validation.md: validation plan and current results.
• docs/benchmarks.md: how performance is measured, and first numbers.
• docs/data-provenance.md: where every dataset comes from.
• docs/python.md: the Python bindings.
• docs/README.md: the full documentation index.
• docs/prior-art.md and docs/history.md: the survey and the lineage.

Contributing

Read CONTRIBUTING.md first. It sets out the clean-room rule: what may be learned from other codes, what may be ported, and what may never enter this tree.

License

MIT. See LICENSE.