e/Formula unit

Information
has gloss	eng: A formula unit in chemistry is the empirical formula of an ionic or covalent network solid compound used as an independent entity for stoichiometric calculations. It is the lowest whole number ratio of ions represented in an ionic compound. Examples include ionic NaCl and K2O and covalent networks such as SiO2 and C (as diamond or graphite).
lexicalization	eng: formula unit
instance of	(noun) a representation of a substance using symbols for its constituent elements formula, chemical formula