Density functional calculations at the B3LYP/LanL2DZ+(f,d,p) level have identified two hydrogen bonding motifs for the title molecule, a C-4h eclipsed and a D-4 staggered structure. The eclipsed structure is calculated to be only about 0.8 kcal/mol more stable than the staggered structure when unscaled zero point energies are considered. The two structures can be distinguished in an X-ray crystallographic analysis on the basis of the Pt-P-O-P dihedral angle without the need to explicitly locate hydrogen atoms in the structure. Calculated vibrational frequencies and Assignments are generally in very good agreement with the available experimental information. One notable exception to this agreement is the experimentally observed 232 cm(-1) Raman transition that was previously assigned to a nonspecific ring bending mode and is currently reassigned to the symmetric Pt2P8 stretching mode.