Polyhedral symbol

The polyhedral symbol is sometimes used in coordination chemistry to indicate the approximate geometry of the coordinating atoms around the central atom. One or more italicised letters indicate the geometry, e.g. TP-3 which is followed by a number that gives the coordination number of the central atom.^[1] The polyhedral symbol can be used in naming of compounds, in which case it is followed by the configuration index.^[1]