Ab initio calculations on the structures and energetics of Li₄OH, Li₃NaOH, and Li₂Na₂OH isomers

We performed ab initio electronic structure calculations on the structures and energetics of the mixed hyperalkaliated hydrogen oxides Li₄OH, Li₃NaOH, and Li₂Na₂OH. Five equilibrium geometries exist for each complex of Li₄OH and Li₃NaOH, and seven minima were located for Li₂Na₂OH. The calculated dissociation energies for the possible dissociation pathways are all endothermic. The global minimum structures of the three complexes have C_2v symmetry and contain a hydrogen-bridged, Li-H-Li, three-centered skeleton. We also investigated the charge redistribution within these complexes in their ionic forms. The energetic factors governing the construction of the equilibrium structures and their bonding properties are analyzed.