Geant4: Particle Simulation Toolkit in Nixpkgs

doc/packages/geant4.section.md

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# Geant4 {#geant4}

[Geant4](https://www.geant4.org/) is a toolkit for simulating how particles pass through matter. It is available through the `geant4` package.

## Setup hook {#geant4-hook}

The setup hook included in the package applies the environment variables set by the [`geant4.sh` script](https://github.com/Geant4/geant4/blob/master/cmake/Modules/G4ConfigureGNUMakeHelpers.cmake#L4-L55), which is typically necessary for compiling `make`-based programs that depend on Geant4.

## Datasets {#geant4-datasets}

All of [the Geant4 datasets provided by CERN](https://geant4.web.cern.ch/support/download) are available through the `geant4.data` attrset.

### Setup hook {#geant4-datasets-hook}

The hook provided by the packages in `geant4.data` will set an appropriate environment variable in the form of `G4[...]DATA`. For example, for the `G4RadioactiveDecay` dataset, the `G4RADIOACTIVEDATA` environment variable is set to the value expected by Geant4.

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Title: Geant4: Particle Simulation Toolkit in Nixpkgs

Summary

This section describes the Geant4 toolkit available in Nixpkgs for simulating particle interactions with matter. It explains how to use the provided setup hook, which configures environment variables required for compiling Geant4-dependent programs. It also details the availability of Geant4 datasets through the `geant4.data` attrset and the corresponding setup hook that sets environment variables for each dataset.