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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
_atom_analytical.chemical_species
Name:_atom_analytical.chemical_species
Definition:
Chemical formula of the species to which the corresponding
_atom_analytical.chemical_species_mass_percent refers.
The following rules apply in the construction of the formula:
1. Only recognized element symbols may be used.
2. The first element corresponds to the analyte. The remaining
elements should be given in alphabetical order by symbol.
3. Each element symbol is followed by a 'count' number. A count of
'1' may be omitted.
4. A space or parenthesis must separate each cluster of (element
symbol + count). A formula cannot begin with a parenthesis.
5. Where a group of elements is enclosed in parentheses, the
multiplier for the group must follow the closing parentheses.
That is, all element and group multipliers are assumed to be
printed as subscripted numbers.
Examples:| 'Fe2 O3' |
| Li |
| 'Si O2' |
| 'Ca S O4 (H2 O)2' |
Type: Text
Category:
atom_analytical