Periodic ab initio calculations of orthoboric acid

Periodic ab initio calculations for orthoboric acid were performed. Geometr ies of a monolayer and a three-dimensional molecular crystal were optimized . Intermolecular interactions within the layer are found to be about three times stronger than the interaction between layers. Layer buckling is shown to be caused by interlayer interactions. Deformation density maps are give n and changes in the density distribution induced by intermolecular interac tions are discussed. (C) 2000 American Institute of Physics. [S0021-9606(00 )30627-4].