Dimethyl phosphate: Stereoelectronic versus environmental effects

Structure and bonding of dimethyl phosphate (DMP) in vacuo and in the cryst al phase is investigated using density functional theory calculations with gradient corrections for the exchange-correlation functional. Calculated st ructural properties agree well with experiment and previous high-level ab i nitio results. Analysis of the chemical bonding in terms of localized Wanni er orbitals allows us to compare stereoelectronic effects to those of the e nvironment. It is found that the latter play a much more critical role for the conformational flexibility of DMP.