VCI calculations account for vibration correlation effects and are based on potential
energy surface as generated from the SURF program) and a basis of VSCF modals.
All VCI calculations will be performed state-specific, i.e. for each vibrational mode an individual
VCI calculation will be performed. As VCI calculations may require substantial computer resources, these
calculations can be as expensive as the potential energy surface generation.
Currently, two different VCI programs
(configuration selective and conventional) are available (see below). The different versions of the
configuration selection VCI program and the underlying configuration selection scheme are described in
detail in:
G. Rauhut, Configuration Selection As a Route Towards Effcient Vibrational Configuration
Interaction Calculations, J. Chem. Phys. 127, 184109 (2007).