Domain based local pair natural coupled cluster method for symmetric and periodic systems

The aim of the project is to develop a variant of coupled cluster (CC) method based on orbitals that reflect the symmetry of the system. The symmetry is used to calculate and employ only a unique set of cluster amplitudes, molecular integrals, and residuals. In order to further reduce the computational cost, the method uses the techniques of the domain-based local pair natural CC method. Most importantly, this will allow application of CC methods for ground and excited states for periodic systems, but the same ideas can be used to employ symmetry for large molecules.