THEORETICAL-STUDY OF THE MULTIMODE PEIERLS DISTORTION IN THE POLYDECKER SANDWICH COMPOUND [NI(H5C3B2)]INFINITY

A semiempirical crystal orbital formalism based on an INDO Hamiltonian is employed to calculate the energy and the electronic structure of the one-dimensional polydecker sandwich compound [Ni(H5C3B2)]infinity. For the nondistorted system a number of energetically close lying electronic configurations was found. Their behaviour as a function of dimerization coordinates for various kinds of spatial dimerization, including distortions of lattice coordinates, intramonomer coordinates, and a superposition of both types of distortions, was studied. A discussion of the computational results on the basis of simple tight-binding approaches as well as exact analytical results for one-dimensional systems is presented.