Bethe–Salpeter correlation energies of atoms and molecules

A variety of approaches is presented for the computation of atomic and molecular correlation energies based on the Bethe-Salpeter equation in the framework of the adiabatic-connection fluctuation-dissipation theorem. The performance of the approaches is assessed by computing the total energies of the atoms H-Ne, the atomization energies of the HEAT set of small molecules as well as by determining the bond lengths and harmonic vibrational frequencies of the metal monoxides MO with M = Ca-Zn.