use-chemical-formula

Small chemical formula primitives for RustUse chemistry crates.

use-chemical-formula represents structural formulas such as H2O, CO2, NaCl, Ca(OH)2, Al2(SO4)3, and CuSO4·5H2O. It provides lightweight parsing, display formatting, and expanded element counts without becoming a chemistry engine.

What this crate provides

Item	Purpose
`ChemicalFormula`	Parsed chemical formula with optional hydrate parts
`FormulaPart`	A contiguous formula part
`FormulaTerm`	An element term or grouped term
`ElementSymbol`	Basic chemical-symbol shape validation
`ElementCount`	Positive element count
`FormulaGroup`	Parenthesized formula terms with a multiplier
`FormulaMultiplier`	Positive group or hydrate multiplier
`HydratePart`	Dot-separated hydrate formula part
`FormulaParseError`	Structured parse errors
`FormulaValidationError`	Structured construction and validation errors

Installation

[dependencies]
use-chemical-formula = "0.1.0"

Quick Examples

Parse a grouped formula

use use_chemical_formula::ChemicalFormula;

# fn main() -> Result<(), use_chemical_formula::FormulaParseError> {
let formula = ChemicalFormula::parse("Ca(OH)2")?;
let counts = formula.element_counts();

assert_eq!(formula.to_string(), "Ca(OH)2");
assert_eq!(counts.get("Ca"), Some(&1));
assert_eq!(counts.get("O"), Some(&2));
assert_eq!(counts.get("H"), Some(&2));
# Ok(())
# }

Parse a hydrate formula

use use_chemical_formula::ChemicalFormula;

# fn main() -> Result<(), use_chemical_formula::FormulaParseError> {
let formula = ChemicalFormula::parse("CuSO4.5H2O")?;
let counts = formula.element_counts();

assert_eq!(formula.to_string(), "CuSO4·5H2O");
assert_eq!(counts.get("Cu"), Some(&1));
assert_eq!(counts.get("S"), Some(&1));
assert_eq!(counts.get("O"), Some(&9));
assert_eq!(counts.get("H"), Some(&10));
# Ok(())
# }

Scope

Represents formula structure with elements, counts, groups, and hydrate parts.
Parses common formula notation with . or · hydrate separators.
Expands total element counts after group and hydrate multipliers.
Validates basic element-symbol shape only.
No periodic-table database validation.
No molecular geometry, bonding, reactions, stoichiometry, molar mass, pH, solutions, thermochemistry, or simulation.
No parser-framework ambitions; the parser is intentionally small and direct.

Relationship to `use-chemistry`

use-chemical-formula is a focused child crate for formula primitives. The use-chemistry umbrella crate reexports it alongside element, isotope, periodic-table, atomic-number, atomic-mass, and electron-shell helpers.

use-chemical-formula 0.1.0