ABINITIO STUDY OF BORON, NITROGEN, AND BORON-NITROGEN CLUSTERS POTENTIAL-ENERGY SURFACE OF B4 AND TOTAL ATOMIZATION ENERGIES OF B2, B3, AND B4

Abstract

Abstract The potential energy surface of B4 has been studied ab initio using extended basis sets and coupled-cluster methods. The ground state (1A1g) is a singlet square that undergoes pseudo-Jahn-Teller distortion to a rhombic structure (1Ag), but the energy gain is so small that the effective structure will be square at all practical temperatures. Total atomization energies ΣDO (kcal/mol) for B2 (62.2±2), B3 (189.1±2–192.6±2), and B4 (312.2±2) are computed by a modification of GAUSSIAN-1 (G1) theory. The validity of scaling and bond-additivity schemes for computing binding energies of higher clusters is discussed.