Modified Regional Self-Interaction Correction Method Based on the Pseudospectral Method NakataAyako TsunedaTakao HiraoKimihiko 2010 A modification of the regional self-interaction correction (RSIC) scheme (Tsuneda et al., <i>J. Comput. Chem.</i> <b>2003</b>, <i>24</i>, 1592), pseudospectral RSIC (PSRSIC), is proposed to eliminate the self-interaction errors (SIEs) especially in core regions. PSRSIC reduces the SIEs by substituting the HF exchange energy density calculated with the use of the pseudospectral technique for the exchange energy in the SI-domain region. PSRSIC is combined with the long-range correction (LC) scheme. TDDFT calculations with LC-PSRSIC yield all of the core-, valence-, Rydberg-, and charge-transfer-excitation energies with reasonable accuracy. Core-ionization energies are also well-reproduced by LC-PSRSIC.