polyhedral symbol

https://doi.org/10.1351/goldbook.PT06792
The polyhedral symbol indicates the geometrical arrangements of the coordinating atoms about the @[email protected] It consists of one or more capital italic letters derived from common geometric terms (tetrahedron, square plane, octahedron, etc.) which denote the idealised geometry of the @[email protected] around the @[email protected] centre, and an arabic numeral that is the @[email protected] of the @[email protected] The polyhedral symbol is used as an affix, enclosed in parentheses, and separated from the name by a hyphen. Examples are T-4, SP-4, TBPY-5, SPY-5, OC-6, and CU-8.
Source:
PAC, 1997, 69, 1251. (Glossary of terms used in bioinorganic chemistry (IUPAC Recommendations 1997)) on page 1292 [Terms] [Paper]