Electronic and Spectroscopic Properties of La2@C112 Isomers

Abstract

Among the 3352 isolated pentagon rule(IPR) isomers and 129073 non-IPR isomers satisfying adjacent pentagon pairs(APPs)≤2 of fullerene C112, the lowest-energy IPR and non-IPR isomers of C112 and C1126- have been fully screened by the density functional tight-binding(DFTB) and density functional theory(DFT) methods for studying the electronic and spectroscopic properties of La2@C112. The structural features and infrared and absorption spectra of those isomers were analyzed in detail, and the characteristic fingerprint absorption peaks were assigned. To clarify the relative stabilities of La2@C112 isomers at high temperature, entropy contributions were determined at the B3LYP level. IPR isomer La2@C112(C2:860136) is not the lowest-energy isomer but is one of the most important isomers. This is the first work that considers non-IPR C112 isomers when exploring the structure and properties of La2@C112.