Vibrational configuration interaction VCI

Hirata et al. used the vibrational self-consistent field (VSCF), vibrational configuration-interaction (VCI), and vibrational second-order Moller-Plesset perturbation (VMP2) methods. The VSCF expressed the vibrational wave functions as products of 52 harmonic oscillator (HO) wave functions. The VCI wave function was a linear combination of the 2000 lowest-energy VSCF model products. The obtained vibrational corrections to V(F, H) and V(F, F) were 18.4Hz and — 42.9 Hz, respectively. The vibrational correction... 

Christiansen has reviewed the reeently developed theoretieal methods for the calculation of vibrational energies and wavefunetions. The main focus is on wavefunction methods using the vibrational self-eonsistent field (VSCF) method as starting point, and ineludes vibrational eonliguration interaction (VCI), vibrational Moller-Plesset (VMP), and vibrational coupled cluster (VCC) approaches. The eonvergenee of these different sets of methods towards the full vibrational configuration interaction (FVCI) result has been discussed as well as the application of this formalism to determine vibrational contributions to response properties. 

Tab. 3.1 Selected vibrational energies (cm ) of H5OJ calculated by a variety of methods and experiment for the OH-monomer stretches. 2d+2d are the adiabatic 4d calculations of Ref [56], 4d are the fully coupled 4d calculations of Ref [27], CC-VSCF are the correlation-consistent vibrational self-consistent field calculations of Ref [58] and VCI are the virtual configuration interaction calculations of Ref [27]. The potential used in these calculations is indicated after the back-slash.

---