First-principles calculations of the structural, electronic, vibrational and magnetic properties of C_{60} and C_{48}N_{12}: a comparative study

TL;DR

This study uses first-principles calculations to explore the structural, electronic, vibrational, and magnetic properties of a novel azafullerene ${\rm C}_{48}{\rm N}_{12}$, revealing its unique features and potential optical applications.

Contribution

It provides the first detailed computational analysis of ${\rm C}_{48}{\rm N}_{12}$, highlighting its structural and electronic distinctions from ${\rm C}_{60}$ and its enhanced optical nonlinearities.

Findings

${\rm C}_{48}{\rm N}_{12}$ has 116 vibrational modes, equally split between IR and Raman activity.

The molecule exhibits unique NMR spectral signals for nitrogen and carbon.

Enhanced third-order optical nonlinearities suggest potential in photonics applications.

Abstract

In this work, we perform first-principles calculations of the structural, electronic, vibrational and magnetic properties of a novel ${\rm C}_{48}{\rm N}_{12}$ azafullerene. Full geometrical optimization shows that ${\rm C}_{48}{\rm N}_{12}$ is characterized by several distinguishing features: only one nitrogen atom per pentagon, two nitrogen atoms preferentially sitting in one hexagon, ${\rm S}_{6}$ symmetry, 6 unique nitrogen-carbon and 9 unique carbon-carbon bond lengths. The highest occupied molecular orbital of ${\rm C}_{48}{\rm N}_{12}$ is a doubly degenerate level of $a_{g}$ symmetry and its lowest unoccupied molecular orbital is a nondegenerate level of $a_{u}$ symmetry. Vibrational frequency analysis predicts that ${\rm C}_{48}{\rm N}_{12}$ has in total 116 vibrational modes: 58 infrared-active and 58 Raman-active modes. ${\rm C}_{48}{\rm N}_{12}$ is also characterized by 8 $^{13}{\rm C}$ and 2 $^{15}{\rm N}$ NMR spectral signals. Compared to ${\rm C}_{60}$, ${\rm C}_{48}{\rm N}_{12}$ shows an enhanced third-order optical nonlinearities which implies potential applications in optical limiting and photonics.