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Using DFT GGA calculations, electronic structure and magnetic properties of wide family of transition metal trihalides (TMHal 3 ) (Zr, Ti and Nb iodides, Mo, Ru, Ti and Zr bromides and Ti or Zr chlorides) are investigated. These structures consist of transition metal atoms chains surrounded by halides atoms.Chains are connected to each other by weak interactions. All TMHal 3 compounds were found to be conductive along chain axis except of MoBr 3 which is indirect gap semiconductor. It was shown that NbI 3 and MoBr 3 have large magnetic moments on metal atoms (1.17 and 1.81 µ B , respectively) but other TMHal 3 materials have small or zero magnetic moments. For all structures ferromagnetic and antiferromagnetic phases have almost the same energies. The causes of these properties are debated.

Theoretical simulations of embedding and relaxation of buckminsterfullerene C 60 molecules chemisorbed on representative surfaces and inside a bulk silicon lattice were performed using both the generalized gradient density functional theory (GGA-DFT) and the self-consistent-charge density-functional tight-binding (DFTB) molecular dynamics (DFTB/MD) methods. We chose fullerene molecules as representative models for general quantum dots on the surface or inside bulk a semiconductor, in this case silicon. If a single C 60 molecule is chemisorbed on (001) and (111) silicon slab surfaces, static GGA-DFT calculations show that the C 60 molecule deformation was very small and the C 60 binding energies were roughly around 4 eV. In these configurations, the analysis of the charge distributions shows that the charge of C 60 molecules on the (001) and (111) silicon surfaces was only between -2 to -3.5 electrons, respectively, that is correlates well with number of C-Si bonds linking the fullerene molecule and the silicon surface. On the other hand, static  Current address: Atotech Deutschland GmbH, 10553 Berlin, Germany GGA-DFT calculations of C 60 molecule relaxation inside suitable hollow spheres in the bulk silicon were performed. After the silicon bulk-C 60 system relaxation, we investigated electronic density of states (DOS), partial DOS and charge distribution. These calculations confirm that the C 60 molecule remains stable inside bulk silicon having deformation energy values of between 11 and 15 eV for geometries with different rotational C 60 configurations, respectively. Formation of some C-Si bonds cause local silicon amorphization and corresponded electronic charge uptake on the embedded fullerene cages. According to еру charge analysis, these quantum dots can accept up to 20 excess electrons, wherein while the main charge contribution is located on the carbon atom bonded to silicon atoms. The dynamic embedding process was modeled using the DFTB/MD method by placing a C 60 molecule on top of a Si (111) slab surface and further exposition to a stream of silicon dimers with kinetic energies equivalent to a temperature of ~723 K directed to the C 60 -silicon surface. After the final MD shot, the resulting geometry was fully relaxed. These calculations show that during landing of the C 60 molecule on the silicon surface and subsequent overgrowth by silicon, C 60 molecule remains stable inside bulk silicon, wherein the C 60 molecule adopts a deformation energy of about 17.8 eV and the overgrowth process leads to a local silicon amorphization, in qualitatively good agreement with the static GGA-DFT calculations.

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