Citation: Zheng, Li-Min; Duan, Chun-Ying; Ye, Xiang-Rong; Zhang, Li-Yi; Wang, Cheng; Xin, Xin-Quan (1998). Synthesis, crystal structure and magnetic properties of a novel mixed-valence copper phosphonate: Na2Cu15(hedp)6(OH)2(H2O) (hedp = 1-hydroxyethylidenediphosphonate) ‡. Journal of the Chemical Society, Dalton Transactions, , pp. 905-.