Performance assessment of density-functional methods for study of charge-transfer complexes.
Various density functionals are applied to a number of weakly bound intermolecular pi-pi charge-transfer (CT) complexes. Most functionals, including the recently developed mPWPW91 and mPW1PW91, grossly underestimate experimental excitation energies; good agreement is obtained only with the half-and-half hybrid BH&HLYP functional. PW91PW91 provides the best agreement with intermolecular distances measured in crystal, while the BH&HLYP values are about 0.1 A too long. Various hybrid functionals with nonlocal exchange correction provide binding energies that compare favorably with the experimental heats of formation measured in solution.
Liao
Meng-Sheng
MS
Department of Chemistry & Biochemistry, Utah State University, Logan, Utah 84322-0300, USA.
Lu
Yun
Y
Scheiner
Steve
S