NEW REFINEMENT OF THE CRYSTAL-STRUCTURE OF O-P2O5

The crystal structure of o-modification of diphosphorus pentaoxide was refined at 295 K. It consists of a network of [PO4] tetrahedra linked by three common apices. Moreover, this o-modification of P2O5 is also found to crystallize in the orthorhombic system with the space group Fdd2 and the lattice parameters a = 16.314(2) Angstrom, b = 8.115(3) A ngstrom, c = 5.265(9) Angstrom, Z = 8, and D-calc = 2.705 (g . cm(-3)) . The main value of the P-O length is estimated to be 1.543 Angstrom. As expected, the nonbridging P-O bonds, equal to 1.445 Angstrom, are s horter than the bridging ones which average 1.582 Angstrom. The struct ure parameters are refined to a final R of 0.0351 (wR = 0.0643) for 55 0 independent reflections [I > 3 sigma(I)]. (C) 1996 Academic Press.