Output formats

MathML

Presentation MathML via Nokogiri. The headline semantic fix: prefix isotopes bind to the atom (^14C → <msup><mi>C</mi> <mn>14</mn></msup>), not to a phantom empty element.

Text

Canonical AsciiChem text. Round-trip conformance: parse(s).to_text == s. The Text formatter is the canonicaliser.

HTML

Inline HTML with <sub> and <sup> tags. Suitable for pages that don’t want to load MathJax.

LaTeX

Wrapped in mhchem’s \ce{...}. Requires \usepackage[version=4]{mhchem} in the preamble.

SVG (linear)

Text rendered inside an SVG <text> element. Self-contained vector output without external dependencies.

StructuralSvg

2D structural diagrams via elkrb graph layout. For molecules with bonds, produces skeletal formulae. For crystals, projects fractional coordinates to 2D with unit cell outline (v0.16+).

Model JSON

The canonical wire form (asciichem-model v1) — the interchange format every implementation emits and ingests.

SMILES

Deterministic re-emission of ingested structures; aspirin and naphthalene round-trip exactly.

Molfile (V2000)

Connection-table output with authored coordinates (a deterministic 2D layout is computed when the model has none).

CML

Chemical Markup Language via the chemicalml gem. Native wire for all constructs (v0.9-v0.11); aci: extension namespace as backwards-compat fallback.

Usage

formula = AsciiChem.parse("H_2O")

formula.to_mathml   # MathML XML string
formula.to_text     # "H_2O"
formula.to_html     # '<span class="asciichem">H<sub>2</sub>O</span>'
formula.to_latex    # "\\ce{H2O}"
formula.to_svg      # SVG XML string
formula.to_structural_svg  # structural SVG (diagrams)
formula.to_cml      # CML XML string

CLI

asciichem convert -i "H_2O" -t mathml   # default
asciichem convert -i "H_2O" -t html
asciichem convert -i "H_2O" -t latex
asciichem convert -i "H_2O" -t cml