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International
Tables for Crystallography Volume G Definition and exchange of crystallographic data Edited by J. R. Hester and B. McMahon © International Union of Crystallography 2026 |
International Tables for Crystallography (2026). Vol. G. Early view chapter
https://doi.org/10.1107/97809553602060001011 Chapter 4.2 Core dictionary (coreCIF) |
Core dictionary version 3.3.0
_chemical_formula.moiety
Name:_chemical_formula.moiety
Alias:
_chemical_formula_moiety
Definition:
Formula with each discrete bonded residue or ion shown as a
separate moiety. See the CHEMICAL_FORMULA category description
for rules for writing chemical formulae. In addition to the
general formulae requirements, the following rules apply:
(1) Moieties are separated by commas ','.
(2) The order of elements within a moiety follows general rule
(5) in CHEMICAL_FORMULA.
(3) Parentheses are not used within moieties but may surround
a moiety. Parentheses may not be nested.
(4) Charges should be placed at the end of the moiety. The
charge '+' or '-' may be preceded by a numerical multiplier
and should be separated from the last (element symbol +
count) by a space. Pre- or post-multipliers may be used for
individual moieties.
Examples:| 'C7 H4 Cl Hg N O3 S' |
| 'C12 H17 N4 O S 1+, C6 H2 N3 O7 1-' |
| 'C12 H16 N2 O6, 5(H2 O1)' |
| '(Cd 2+)3, (C6 N6 Cr 3-)2, 2(H2 O)' |
Type: Text
Category:
chemical_formula
