About the code

Cc4s is a high-performance open-source coupled cluster simulation code.

The coupled cluster method is used as a so-called post Hartree-Fock method for solving the electronic Schrödinger equation (wikipedia).

The main application of cc4s is to study the electronic properties of solid-state systems. Solving the coupled cluster equations for these systems is computationally extremely demanding. Therefore we make use of state-of-the-art high-performance libraries such as CTF, an efficient parallel tensor contraction engine, and leverage computational paradigms such as MPI and OpenMP based parallelization.

In general terms, cc4s takes as input a reference wavefunction together with a description of the Coulomb integrals. Currently, interfaces are available for the codes vasp and fhi-aims.