High accuracy many-body calculational approaches for excitations in molecules

Journal Article · Mon Feb 28 04:00:00 EST 2000 · Physical Review Letters

OSTI ID:788053

Grossman, Jeffrey C ^[1]; Rohlfing, Michael; Mitas, Lubos; Louie, Steven G; Cohen, Marvin L

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1. LBNL Library

Two state-of-the-art computational approaches: quantum Monte Carlo and GW with exciton effects [GW-BSE (Bethe-Salpeter equation)] are employed to calculate ionization potentials, electron affinities, and first excited singlet and triplet energies for the silane and methane molecules. Results are in excellent agreement between these dramatically different approaches and with available experiment. The optically forbidden triplet excitation in silane is predicted to lie roughly 1 eV higher than previously reported. In the GW-BSE method, we demonstrate that inclusion of off-diagonal matrix elements in the self-energy operator is crucial for an accurate picture.

• Research Organization: Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
• Sponsoring Organization: USDOE Director, Office of Science. Office of Basic Energy Studies. Division of Materials Sciences; National Science Foundation (US)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 788053
• Report Number(s): LBNL--48695
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 3 Vol. 86; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
ACCURACY
ELECTRONS
EXCITATION
EXCITONS
IONIZATION POTENTIAL
MATRIX ELEMENTS
METHANE
SELF-ENERGY
SILANES
TRIPLETS