chemical_formula
element_expression
element_expression
element_expression
[Suppress:(= | ·)] operations
[Suppress:(= | ·)] operations
[Suppress:(= | ·)] operations
integer operations
integer operations
optional_separator
optional_separator
integer operations
integer operations
integer operations
integer operations
integer operations
integer
integer
integer operations
integer operations
subscript operations
subscript operations
integer
W:(0-9)
subscript operations
element
element
nested_element
nested_element
subscript
subscript
element
element
nested_element
nested_element
nested_element
'('
[suppress]
element_expression
element_expression
')'
[suppress]
subscript
W:(₀-₉)
element
A[cglmrstu]|B[aehikr]?|C[adeflmnorsu]?|D[bsy]|E[rsu]|F[elmr]?|G[ade]|H[efgos]?|I[nr]?|Kr?|L[airuv]|M[cdgnot]|N[abdehiop]?|O[gs]?|P[abdmortu]?|R[abefghnu]|S[bcegimnr]?|T[abcehilms]|U|V|W|Xe|Yb?|Z[nr]
optional_separator
= | ·
= | ·
[suppress]
= | ·
[=·]