TY  - JOUR
A1  - Körzdörfer, Thomas
A1  - Parrish, Robert M.
A1  - Marom, Noa
A1  - Sears, John S.
A1  - Sherrill, C. David
A1  - Bredas, Jean-Luc
T1  - Assessment of the performance of tuned range-separated hybrid density functionals in predicting accurate quasiparticle spectra
T2  - Physical review : B, Condensed matter and materials physics
N2  - Long-range corrected hybrid functionals that employ a nonempirically tuned range-separation parameter have been demonstrated to yield accurate ionization potentials and fundamental gaps for a wide range of finite systems. Here, we address the question of whether this high level of accuracy is limited to the highest occupied/lowest unoccupied energy levels to which the range-separation parameter is tuned or whether it is retained for the entire valence spectrum. We examine several pi-conjugated molecules and find that orbitals of a different character and symmetry require significantly different range-separation parameters and fractions of exact exchange. This imbalanced treatment of orbitals of a different nature biases the resulting eigenvalue spectra. Thus, the existing schemes for the tuning of range-separated hybrid functionals, while providing for good agreement between the highest occupied energy level and the first ionization potential, do not achieve accuracy comparable to reliable G(0)W(0) computations for the entire quasiparticle spectrum.
Y1  - 2012
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/35526
SN  - 1098-0121
VL  - 86
IS  - 20
PB  - American Physical Society
CY  - College Park
ER  -