A Theoretical Study of Carbon Clusters: Equilibrium Geometries and Electronic Structures of C_n

Abstract

In recent years, there has been widespread interest in the theoretical investigation of clusters of atoms (Schaefer 1975, Echt et al. 1981, Muhlback et al. 1982, Messmer 1982, Knight et al. 1984, Ray et al. 1985, Ray 1986). The understanding of the chemistry and physics of clusters is of signal importance in many diverse areas, such as catalysis and combustion. Such clusters are also often used to model bulk solid-state phenomena and their surfaces. Newly developed experimental techniques also make it possible to study the transition from cluster to bulk behavior. Much of the earlier work has been on metal clusters, specifically alkali metal clusters (Knight et al. 1984, Clemenger 1985), where “magic numbers” have been identified in the relative populations of aggregates of atoms. In a cluster experiment, the existence of these magic numbers are identified as local maxima in the cluster abundance spectrum at certain “magic” cluster sizes. For these metals, the spherical jellium model (Knight et al. 1984, Chou et al. 1984) provide a good understanding of the existence of magic numbers, predicted to occur at 2, 8, 20, 40, etc. Similar work has been reported on the formation of “magic clusters” for molecules (Beuhler 1982) and rare gases (Echt et al. 1981).