This repository contains the specification for the ACE format—as well as a few supporting formats.

The information contained in this document was formerly Appendix F of the MCNP5 manual, but has been put in its own document to enable wider distribution. Currently the specification only contains a portion of the full specification. More will be added in time.

The document itself is ACEFormat.pdf and can be downloaded/viewed without having to clone or download the entire repository.

Please note: this document is not complete at this time.

This fork includes a conversion of the original ACE Format document to Markdown, making the specification easier for AI systems and other tools to consume. The original LaTeX sources remain authoritative, and the Markdown version is generated from them.

The Markdown version is generated from the LaTeX sources:

python3 tools/convert_to_markdown.py

The converter requires Pandoc and writes ACEFormat.md. Its compatibility entry point expands the custom ACE table environments into standard LaTeX tables before Pandoc converts them; ACEFormat.md should therefore not be edited by hand.

If you discover problems with the specification, please file an issue on GitHub. This will allow those involved to investigate and keep a record of what has been done. Note that we are not modifying or extending the format at this time; we are only looking for bugs in the format specification.

This format is covered under the license agreement contained in the LICENSE file.