Embedded math

Chemistry publications embed mathematics everywhere: equilibrium constants (K_c = [P]/[R]), rate laws (rate = k[A]^2[B]), Arrhenius (k = A e^{-E_a/RT}).

AsciiChem does not reinvent math typography. Backtick-delimited runs are parsed by Plurimath’s AsciiMath parser, then embedded in the chemistry model as an EmbeddedMath node wrapping a Plurimath::Math::Formula.

Syntax

Surround any math expression with backticks:

`K_c = [P]/[R]`

${\displaystyle K_c=\frac{P}{R}}$

`k = A e^{-E_a/(RT)}`

${\displaystyle k=A{e}^{-\frac{E_a}{RT}}}$

`rate = k[A]^2[B]`

${\displaystyle rate=k{\left[A\right]}^2\left[B\right]}$

Where it appears

EmbeddedMath nodes can appear anywhere a top-level node can — at the formula root, inside a molecule (rare), or as a reaction condition (intended for v2).

The most common use is at the formula root, paired with chemistry:

H_2 + I_2 <=> 2HI `K_c = [HI]^2 / ([H_2][I_2])`

${\mathrm{H}}_2+{\mathrm{I}}_2\rightleftharpoons 2\mathrm{H}\mathrm{I}{\displaystyle K_c=\frac{{\left[HI\right]}^2}{\left[H_2\right]\left[I_2\right]}}$

Rendering

For MathML output, AsciiChem calls Plurimath::Math::Formula#to_mathml and strips the outer <math> wrapper so the fragment slots cleanly into AsciiChem’s surrounding <mrow>.

For text output, the original backtick-delimited source is reproduced verbatim — round-trip is exact.

Why Plurimath?

• It already handles AsciiMath, LaTeX, UnicodeMath, OMML, and MathML.
• It’s model-driven, with the same architectural values as AsciiChem.
• Reusing it keeps AsciiChem focused on chemistry; math is a solved problem with a good library.

Limitations

• Backticks cannot be nested in v1. Use Plurimath’s native syntax for complex expressions; the embedded source is opaque to AsciiChem.
• Whitespace inside the backticks is preserved verbatim.