Influence Of Basis Sets On The Energy-level Calculations Of Fullerene Molecules

In this thesis, we briefly review the basis set theory in quantum chemistry, and calculate the energy levels of C60 and C70 molecules with different basis sets. The calculations are based on the density functional theory and the BLYP functional. The calculating tool is the DMol3 package.We judge the validity of the basis sets by comparison of the calculated results with the photoelectron spectroscopy (PES) data. The results reveal that the TNP, DNP and DND basis sets work fairly well, the DN basis set is inferior, and the MIN basis set is the worst.The energy levels calculated with the TNP, DNP and DND basis sets can play important roles in analyzing light absorption and photoemission experiments.