Property calculations by coupled cluster based linear response theory: dynamic polarizability and van der Waals coefficient

We propose and implement in this paper a highly correlated method for computing dynamic polarizability of closed-shell atoms and molecules and the van der Waals coefficient C6 of atoms within the framework of coupled cluster based linear response theory (CC-LRT). Excitation energies (EE), oscillator strengths and the dynamic dipole polarizability have been computed for He, Be and CH+. The coefficient C6 has been calculated for He and Be. Comparison with the existing data and high quality CI results is found to be quite encouraging, indicating the promise of the method