(N/A) The following rules are applied for writing the formulas of coordination compounds:
$(i)$ The central atom is written first.
$(ii)$ The ligands are then written in alphabetical order.
$(iii)$ Polydentate ligands are also listed in alphabetical order. In the case of abbreviated ligands,the first letter of the abbreviation is used to determine the alphabetical order.
$(iv)$ The formula for the entire coordination entity,whether charged or not,is enclosed in square brackets. When ligands are polyatomic,their formulas are enclosed in parentheses. Abbreviations are also enclosed in parentheses.
$(v)$ There should be no space between the ligands and the metal within the coordination sphere.
$(vi)$ When the formula of a charged coordination entity is written,the charge is indicated outside the square brackets as a superscript on the right side,without the counter-ion charge.
Example: $[Co(CN)_6]^{3-}$.
$(vii)$ The charge of the cation is balanced by the charge of the anion.