Single crystals of α-Ba(2)P(2)O(7), dibarium diphosphate, were obtained under hydro-thermal conditions. The structure belongs to the diphosphate A(2)P(2)O(7) series with A being an alkaline earth cation. α-Ba(2)P(2)O(7) crystallizes isotypically with α-Sr(2)P(2)O(7). All atomic sites have site symmetry m with the exception of two O atoms which reside on general positions. Both Ba(2+) cations are coordinated by nine terminal O atoms from eclipsed diphosphate P(2)O(7) anions to form a three-dimensional network throughout the structure.