Enumeration of heterogroup substituted isomers of α-{V_18−x(As₂)_xO₄₂} and β-{V_18−x(As₂)_xO₄₂} obtained as a result from the implementation of “pov-isomeriser” algorithm (see Table 1).

MxM′18−x	1	2	3	4	5	6	7	8	9
α/rbc	2	10	42	142	380	811	1368	1872	2088
β/prbc	3	25	104	406	1080	2374	3992	5550	6098