Table 6. A priori bond valences (v.u.) for CaNb⁵⁺ ₂(P₄O₁₃)(P₂O₇)O.

	Nb1	Nb2	Ca	P1	P2	P3	P4	∑
O1			0.267 ×2↓	1.733				2
O2		0.782 ×2↓		1.218				2
O3				1 ×2→				2
O4				1.049	0.951			2
O5	0.805 ×2↓				1.195			2
O6			0.316 ×2↓		1.684			2
O7		0.831 ×2↓			1.169			2
O8	0.837 ×2↓					1.163 ×2↓		2
O9			0.348			1.652		2
O10						1.169	0.978	2
O11	0.859 ×2↓						1.141 ×2↓	2
O12		0.261					1.739	2
O13		1.515	0.458					2
∑	5	5	2	5	5	5	5