Ulf Ekström

TL;DR: Dalton is a powerful general‐purpose program system for the study of molecular electronic structure at the Hartree–Fock, Kohn–Sham, multiconfigurational self‐consistent‐field, Møller–Plesset, configuration‐interaction, and coupled‐cluster levels of theory.

TL;DR: ReSpect allows molecules with >100 atoms to be efficiently handled at the four-component level of theory on standard central processing unit-based commodity clusters, at computational costs that rarely exceed a factor of 10 when compared to the non-relativistic realm.

TL;DR: A novel implementation of Kohn-Sham density-functional theory utilizing London atomic orbitals as basis functions is presented, which is the first fully self-consistent implementation of the latter for molecules in very strong magnetic fields.

TL;DR: Generalized second-order vibrational perturbation theory is used to calculate the fundamental frequencies of methane, ethane, benzene, and aniline, comparing B3LYP, BLYP, and Hartree-Fock results and suggesting that the inclusion of electron correlation is not essential for the reliable calculation of cubic and quartic force constants.

TL;DR: The coupled perturbed Kohn-Sham (CPKS) computational scheme for the evaluation of electric susceptibility tensors in periodic systems, recently implemented in the CRYSTAL code, has been extended to third-order and used to obtain static electronic hyperpolarizabilities of zigzag BN nanotubes for the first time.