chemical_formula

element_expressionelement_expression

element_expression

[Suppress:(= | ·)] operations[Suppress:(= | ·)] operations

[Suppress:(= | ·)] operations

integer operationsinteger operations optional_separatoroptional_separator integer operationsinteger operations integer operationsinteger operations

integer operations

integerinteger integer operationsinteger operations subscript operationssubscript operations

integer

W:(0-9)

subscript operations

elementelement nested_elementnested_element subscriptsubscript elementelement nested_elementnested_element

nested_element

'(' [suppress] element_expressionelement_expression ')' [suppress]

subscript

W:(₀-₉)

element

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optional_separator

= | ·= | · [suppress]

= | ·

[=·]