Study on the Electronic Structure and Stability of Some   OPE(oligo-phenylene-ethynylene derivative)-RE3N@C80 Dyads by PM7
  In this paper, we investigated the electronic structure and stability of some mesomorphic OPE-RE3N@C80 dyads from the oligo-phenylene-ethynylene derivatives (OPE) and the trimetallic nitride template endohedral fullerenes (TNT-EMFs) - RE3N@C80 (RE=Sc,Y,La) by using PM7, the updated version of the semi-empirical Hartree-Fock method. In OPE-RE3N@C80, the fullerene cages were modified to have the opened cage (fulleroid) structure by addition of OPE on the [6,6] position of the fullerene cages. There was no considerable charge transfer between OPE and fullerene cage, but the fullerene cages had the remarkable minus charges mainly due to the electron transfer from RE3N to the cage. The calculated electronic spectra showed that light absorption bands of OPE-C80 were more red-shifted than that of OPE-RE3N@C80 and all of OPE-RE3N@C80 seem to have a couple of Vis-NIR absorption peaks. 
Kye-Ryong Sin, Sun-Gyong Ko, Hong-Gol O, Song-Jin Im
physics.chem-ph