Calculations of Molar Fractions of the IPR C78 Fullerenes

Abstract

There are five isolated‐pentagon‐rule (IPR) satisfying isomers of C78. In contradiction to theoretical predictions, only three isomers were observed in experiments and the fourth one was not identified until very recently. In this work we calculate structural and energetic data of the five IPR C78 fullerenes, namely we optimized their geometries with the B3LYP density‐functional method using the standard 4‐31G basis set (B3LYP/4‐31G), calculated separation energies at the B3LYP/6‐311G* level (B3LYP/6‐311G*//B3LYP/4‐31G), estimated energies of low lying electronic states with the ZINDO semiempirical method and calculated harmonic vibrational frequencies with the semiempirical SAM1 method. From the obtained data we constructed chirality respecting isomeric partition functions and evaluated molar fractions in the equilibrium isomeric mixture for a wide temperature interval.