ENERGY-MINIMIZED HYDROGEN-ATOM POSITIONS OF KAOLINITE

The H-atom positions within fixed non-H-atom structures of kaolinite have been determined using energy-minimization procedures. Our model treats all H-atom interactions as electrostatic except the intramolecular hydroxyl term which is described using a coulombic subtracted offset Morse potential. All inner-surface hydroxyl groups are found to point almost perpendicular to the layers and therefore appear to be involved in interlayer hydrogen bonding. The orientation of the inner hydroxyl is found to be directed towards the octahedral vacancy.