Deck Editor

Parse, validate, and edit full MCNP decks plus unit-aware decay inventories.

The mcnp-io crate parses whole MCNP input decks into a DeckProblem that round-trips byte-identical when unedited and re-renders single cards canonically after edits. The depletion crate layers a unit-aware DecayInventory over a depletion chain for decay, activity/mass/mole conversions, and chain-topology queries. Both run in the demo below (text only — there is no file access here, so decks load from pasted text, never from files).

Try it

Paste a deck (or load the synthetic L3 lattice sample) and press Parse. The demo shows the cell table, the cell→material inventory map, material and L3 counts, and the validation verdict. Edit a cell’s density, material, universe, lattice, or fill, or change the MODE card, and the re-rendered deck text updates below. ✓ valid means every L3 semantic rule passes; bulleted notes are particle/mode mismatches, which are warnings rather than errors. Numeric edits that are not finite numbers are rejected with an inline error before they reach the solver.

See also

• Theory: Depletion
• Theory: Nuclear data
• Tutorial: Parse MCNP output
• Tutorial: Run depletion
• Demo: MCNP I/O
• Crate docs: crates/mcnp-io/src/lib.rs