An ab initio Study of the Crystalline Structure of Sulfuric Acid (H2SO4)- The Point Charge Model.

The point charge model is used to calculate the crystal structure of sulfuric acid H2SO4 with the 6-31 G basis set. The point charge model accurately reproduces the structural trends which occur in transforming from the gas to the solid phase. The calculated crystal structure of sulfuric acid is in reasonably good agreement with both the X ray and neutron diffraction structures. The point charge model is shown to precisely simulate the deformation forces which are present in the solid upon crystallization. The point charge model exhibits a definite shift of electron density from the bridging hydrogens to the acceptor atoms, identical to those found in other ab inito studies. The calculated crystal structures are insensitive to the magnitude of the point charges.