HARDNESS, CHEMICAL-POTENTIAL, AND VALENCY PROFILES OF MOLECULES UNDER INTERNAL ROTATIONS

The hardness (eta), chemical potential (mu), and molecular valency (V-M) profiles of C2H4, H(3)X-YH3 (X, Y = C, Si), B2H6, and HCP have been calculated ab initio using the 6-31G** basis set. These profiles correspond to rotation around the C=C bond in C2H4 and the X-Y bond in H(3)X-YH3, of the BHBH plane in B2H6, and of the H atom around the midpoint of the CP bond in HCP. The maximum hardness principle has been found to be obeyed in all cases. The eta and mu profiles are generally opposite in nature. With the exception of B2H6, the V-M is maximum at the ground state equilibrium configuration of a molecule in all cases.