Three-center two-electron bond index profiles of some simple molecules
containing H, Li and B atoms have been calculated using suitable basi
s sets at the HF level. These profiles correspond to the formation of
H-3(+) from H-2 and H+, rotation of the BH2 units of B2H6 and variatio
n of the HLiH angle of LiH3. The three-center bond index is found to b
e maximum near to the geometry of energy minimum. Higher three-center
bond indices are observed for LiH dimer and BH4+ at their equilibrium
geometry than at an alternative structure.