A Theoretical Investigation of the Possible Detection of C24 in Space

TL;DR

This paper uses computational chemistry methods to investigate whether the infrared spectral features observed in space could be caused by the planar graphene form of the C24 carbon cluster, finding it to be the best match.

Contribution

It provides a theoretical analysis of C24 isomers' stability and spectra, identifying the graphene form as the most likely astronomical carrier.

Findings

Graphene C24 best matches observed space spectra.

Density functional and coupled cluster calculations support stability.

Vibrational modes align with astronomical infrared features.

Abstract

Astronomical infrared spectral features at ~6.6, 9.8 and 20 micronm have recently been suggested as being due to the planar graphene form of C24 carbon cluster. Here we report density functional theory and coupled cluster calculations on wavefunctions stability, relative energies, and infrared spectra of four different types of C24 isomers, including the graphene and fullerene forms. The types of vibrational motions under these bands are also discussed. Among the four isomers, we find that the astronomical data are best approximated by the graphene form of C24.