NICHOLS
Monte Carlo Decks in Sublime Text & Notepad++
Syntax highlighting, completions, and color schemes for all four nuclear Monte Carlo codes — MCNP, OpenMC, Serpent, and SCONE — in the two lightweight editors the community actually uses. Ported from OWEN's grammars and snippets. A BelvoirDynamics product.
All Four Codes
MCNP, Serpent, and SCONE syntaxes plus OpenMC Python API highlighting — the only Sublime/Notepad++ package covering all four
Snippets & Completions
OWEN's snippet library ported: pin cells, 17×17 assemblies, criticality arrays, shielding slabs, plus card/keyword/API completions
4 Color Schemes
Classic, Solarized, High Contrast, and Pastel — the same palettes as OWEN, as Sublime color schemes
Run From the Editor
Sublime build systems launch mcnp6, sss2, scone.out, or python on the active deck with Ctrl+B
MCNP 80-Column Guard
Column-80 ruler in Sublime; optional PythonScript line-length checker for Notepad++
Zero Dependencies
Plain config files — copy into your editor and go; fully offline, MIT licensed, sample decks included
v1.0.0 • Sublime Text 4 • Notepad++ 8.x • Windows / Linux / macOS
A BelvoirDynamics Product | ReactorMC
Install — Sublime Text
Download nichols-sublime-v1.0.0.zip, open Preferences > Browse Packages... in Sublime Text, and copy the NICHOLS/ folder from the zip into the Packages/ folder that opens. Highlighting is live immediately for .i, .mcnp, .inp, .serp, .sss, and .scone files.
Pick a scheme via Preferences > Select Color Scheme... > NICHOLS Classic (or Solarized / High Contrast / Pastel). For OpenMC scripts, choose the Python (OpenMC) syntax from View > Syntax.
Install — Notepad++
Download nichols-notepadpp-v1.0.0.zip, then in Notepad++ open Language > User Defined Language > Define your language..., click Import..., and pick each XML from the zip's udl/ folder (MCNP, Serpent, SCONE). Restart Notepad++.
For auto-completion, copy the files in autoCompletion/ into C:\Program Files\Notepad++\autoCompletion\. OpenMC scripts use the built-in Python highlighting; an OpenMC API completion add-on is included — see the README in the zip.
The BelvoirDynamics family
Same domain knowledge, three form factors
NICHOLS carries OWEN's grammars, snippets, and palettes into Sublime Text and Notepad++. When you need more than highlighting — validation, 3D geometry preview, lattice builder, cross-sections — step up to OWEN or GROVES.
OWEN — VS Code extension
Full toolkit: 4-palette highlighting, MCNP reference tracker, ALLEN σ(E) viewer, 3D BEAVRS preview, lattice builder, validation, simulation automation.
GROVES — desktop editor
Air-gap-friendly standalone editor with a built-in 3D viewer, run/sweep workflows, and no toolchain to manage. Windows installer.
Source and releases: github.com/caalh/nichols — MIT licensed.