Intramolecular Charge-Transfer Excitation Energies from Range-Separated Hybrid Functionals Using the Yukawa Potential

Valence and intramolecular charge-transfer excitation energies of middle-sized molecules are calculated by time-dependent density functional theory, with the long-range corrected hybrid functionals employing the recently developed range-separation schemes using the Yukawa potential. The Yukawa potential allows modest mixings of the Hartree-Fock exchange over a wide range of electron-electron distance. The Yukawa variant of the Coulomb-attenuated method (CAM) achieves comparable accuracy in using CAM-B3LYP functional for predicting not only various types excitation energies but also atomization energies, retaining 100% of the exact exchange potential in large interelectron distances. It is demonstrated that the use of the Yukawa potential is advantageous over the conventional range-separation schemes with the error function. (c) 2009 Wiley Periodicals, Inc. Int J QLiantLirn Chem 109: 1905-1914, 2009