Table 1. Comparison of α-Na₂[IrF₆] and β-Na₂[IrF₆].

substance	bond distances in [IrF6]2– (Å)		bond distances in {NaF6} (Å)		calculated density (g/cm3)
α-Na2[IrF6], low temp.	Ir-F1 (4x)	1.946	Na-F1 (2x)	2.248	4.63
	Ir-F2 (2x)	1.940	Na-F1 (2x)	2.284
			Na-F2 (2x)	2.354
	average	1.943	average	2.295
β-Na2[IrF6], high temp.	Ir1-F1 (6x)	1.940	Na1-F2 (2x)	2.204	4.52
	Ir2-F2 (3x)	1.947	Na1-F3 (2x)	2.322
	Ir2-F2 (3x)	1.933	Na2-F1 (2x)	2.407
	mean	1.940	mean	2.311