All-atom ab initio energy minimization of the kaolinite crystal structure

Calculations that minimize the energy and optimize the geometry of all atomic coordinates for two proposed kaolinite crystal structures were performed using a first-principles, quantum chemical code based on local density functional theory. All calculations were performed using published unit-cell parameters. Innerand interlayer H atom positions agree well with those determined by Bish (1993) from neutron diffraction data and confirm a unit cell with C1 symmetry.