Vibrational absorption spectra calculated from vibrational configuration interaction response theory using the Lanczos method.
The Lanczos method is used to efficiently obtain the linear vibrational response function for all frequencies in an arbitrary interval. The complex part of the response function gives the absorption spectrum which can subsequently be analyzed. The method provides a way to obtain global information on the absorption spectrum without explicitly converging all vibrational eigenstates of the system. The tridiagonal Lanczos matrix used to obtain the response functions needs only be constructed once for each operator. Example calculations on cyclopropene and uracil are presented.
Seidler
Peter
P
Department of Chemistry, The Lundbeck Foundation Center for Theoretical Chemistry, University of Aarhus, Langelandsgade 140, DK-8000 Aarhus C, Denmark. seidler@chem.au.dk
Hansen
Mikkel Bo
MB
Gyorffy
Werner
W
Toffoli
Daniele
D
Christiansen
Ove
O