Formulation and implementation of direct algorithm for the symmetry-adapted cluster and symmetry-adapted cluster-configuration interaction method.

Symmetry-adapted cluster and symmetry-adapted cluster-configuration interaction method in the polarizable continuum model: theory of the solvent effect on the electronic excitation of molecules in solution.

In this paper we present the theory and implementation of the symmetry-adapted cluster (SAC) and symmetry-adapted cluster-configuration interaction (SAC-CI) method, including the solvent effect, using the polarizable continuum model (PCM). The PCM and SAC/SAC-CI were consistently combined in terms of the energy functional formalism. The excitation energies were calculated by means of the state-...

Energy gradient method for the ground , excited , ionized , and ž electron - attached states calculated by the SAC symmetry - adapted / ž / cluster r SAC – CI configuration interaction method

A method for calculating the analytical energy gradient of the ground, excited, ionized, and electron-attached states Ž . Ž . calculated by the SAC symmetry-adapted cluster rSAC–CI configuration interaction method was formulated and implemented. This method adapts to the selection procedure of the linked and unlinked operators in the current SACrSAC–CI code. It was applied to various molecules ...

Excited-state geometries and vibrational frequencies studied using the analytical energy gradients of the direct symmetry-adapted cluster-configuration interaction method. I. HAX-type molecules.

In this series of studies, we systematically apply the analytical energy gradients of the direct symmetry-adapted cluster-configuration interaction singles and doubles nonvariational method to calculate the equilibrium geometries and vibrational frequencies of excited and ionized states of molecules. The harmonic vibrational frequencies were calculated using the second derivatives numerically c...

Analytical energy gradient of the ground, excited, ionized and electron-attached states calculated by the SACrSAC-CI method

The method of calculating the analytical energy gradients for the ground, excited, ionized and electron-attached states Ž . Ž . calculated by the SAC symmetry adapted cluster rSAC-CI configuration interaction method is formulated and implemented. It is adapted with the configuration selection procedure used in the SACrSAC-CI method. The performance of the method is investigated for the Li and C...

Title Electronic spectra and photodissociation of vinyl chloride: A symmetry-adapted cluster configuration interaction study