“…In addition to the atomic and molecular systems that contain heavy elements, the DK2 method was applied to crystalline systems with the crystal orbital approach under periodic boundary conditions . Their applications include the calculation of spectroscopic constants − such as molecular geometries, frequencies, and dissociation energies, fine structure splittings, , electronic excitation energies, − laser-induced chemiluminescence, , ionization potentials, and electron affinities, as well as electrical properties such as dipole moments, dynamic multipole polarizabilities, dispersion coefficients, − and nuclear quadrupole coupling tensors. , Independent of the work in the Hess group, the DK2 approach was implemented in the framework of the linear combination of Gaussian-type orbitals (LCGTO) approach to density functional theory (DFT) by the Rösch group . Rösch and co-workers applied their LCGTO–DFT approach using the DK2 method to the electronic structure investigations of large molecular systems − and diatomic molecules. − …”