Electronic -Tensor Calculations for Dangling Bonds in Nanodiamonds.

The electronic -tensor calculations are performed for dangling bonds (DBs) introduced into nanodiamonds (NDs) with four different functional groups on their surfaces. For hydrogenated and fluorinated NDs, it is found that -shifts of the latter vary in a much wider range, and the same is also true for the total energy differences between the highest and the lowest energy DBs. In addition, it is shown that the shape of NDs significantly impacts the energetics and -shifts of DBs, whereas the influence of the size is much less pronounced, as is the influence of the presence of one DB in the vicinity of the other, resulting in no substantial change on their magnetic behavior.

Electronic g-tensors of nanodiamonds: Dependence on the size, shape, and surface functionalization.

The electronic g-tensor dependence on the size, shape, and surface functionalization of nanodiamonds (NDs) is theoretically investigated by selecting dangling bonds and single substitutional nitrogen atoms as a main source of the unpaired electrons. The performed g-tensor calculations reveal that aforementioned paramagnetic impurities introduced into octahedrally shaped ND of CH size behave in a very similar manner as those embedded into a smaller octahedral model of CH size. Since cubic and tetrahedral NDs-CH and CH-demonstrate a wider range of g-shift values than octahedral systems, the g-tensor dependence on different shapes can be considered as more pronounced.

On the magnetic properties of nanodiamonds: Electronic g-tensor calculations.

The electronic g-tensor calculations are carried out for various paramagnetic defects introduced into hydrogenated diamond nanocrystal CH, showing that such a system can be successfully used to model magnetic properties of nanodiamonds (NDs) with paramagnetic centers containing no vacancies. In addition, it is revealed that, depending on the geometric positions in ND, paramagnetic centers of the same type produce noticeable variations of the g-tensor values. A side-by-side comparison of the performance of effective nuclear charge and spin-orbit mean field (SOMF) approaches indicates that the latter is more sensitive to the quality of basis sets, especially concerning diffuse functions, the inclusion of which is found to be nonbeneficial.

A first-principles study of structural and elastic properties of bulk SrRuO3.

We present a first-principles investigation of structural and elastic properties of experimentally observed phases of bulk SrRuO3 - namely orthorhombic, tetragonal, and cubic - by applying density functional theory (DFT) approximations. First, we focus our attention on the accuracy of calculated lattice constants in order to find out DFT approaches that best represent the crystalline structure of SrRuO3, since many important physical quantities crucially depend on change in volume. Next, we evaluate single-crystal elastic constants, macroscopic elastic parameters, and mechanical stability trying to at least partially compensate for the existing lack of information about these fundamental features of SrRuO3.