Limits

Size checks are arithmetic, made before anything is allocated. Two levels: over the soft limit the caller is warned; over the hard limit the operation is refused and the message says what would fit.

Profile	Soft	Hard
standard	table value	table value
generous	2x	2x
warn_only	table value	never refuses

The table (Standard) is: drawn 100,000 / 400,000; supercell 50,000 / 200,000; grid 1,500,000 / 4,000,000; carbon 10,000 / 30,000; nanotube and graphene 50,000 / 200,000; phonons 2,000 / 8,000; analytic Hessian 100 / 300.

API

rust

use xtalforge::core::{Limits, Profile, limits_bounds, limits_check};

let limits = Limits::new(Profile::Standard);
let verdict = xtalforge::core::limits::check_supercell(
    &limits, 10_000, [[2.0, 0.0, 0.0], [0.0, 2.0, 0.0], [0.0, 0.0, 2.0]],
)?;
let (soft, hard) = limits_bounds("standard", "supercell")?;
let report = limits_check("standard", "supercell", 80_000)?;

bash

xtalforge --limits standard cell --params 3 4 5 60 70 80

python

soft, hard = xtalforge.limits_bounds("standard", "supercell")
report = xtalforge.limits_check("standard", "supercell", 80_000)

js

import { limits_bounds, limits_check } from "xtalforge-wasm";
const bounds = limits_bounds("standard", "supercell");
const report = limits_check("standard", "supercell", 80000);

Estimates

• count(value) — formats a count as 52,000 or 1.4 M.
• drawn_atoms(n_atoms, ranges) — cell atoms times the range volume.
• multiplier(p) and supercell_atoms(n_atoms, p) — |det P|.
• grid_shape(lattice, spacing) and grid_points(lattice, spacing) — from the cell lengths, minimum 8 points per axis.
• check_drawn, check_supercell, check_grid, check_phonons and check_hessian return a Verdict { level, estimate, sentence }.
• Limits::bounds(budget) returns (soft, hard); hard is None under WarnOnly.
• Verdict::refused and Verdict::warned are the predicates; a refused operation returns Error::LimitExceeded(verdict) with code limit_exceeded.
• Budget names the estimate; LimitLevel is Ok, Warn or Refuse. UNDO_ATOMS, UNDO_KEEP and HESSIAN_MIB_PER_ATOM are the model constants.

The carbon, nanotube, graphene, phonon and Hessian budgets are part of the table. The builders allocate through the generic supercell/grid paths; a dedicated per-builder check is not exposed, so callers use check_supercell, check_grid, check_phonons or check_hessian with the matching budget.

Surfaces

The CLI has the global --limits {standard,generous,warn-only} flag. Python takes limits_check(profile, budget, estimate); WASM takes the same and returns an object. WASM defaults to standard because browser memory is small.