LCAO and PW DFT calculations of the lattice constant, bulk modulus, cohesive energy, charge distribution, band structure, and DOS for UN single crystal are analyzed. It is demonstrated that a choice of the uranium atom relativistic effective core potentials considerably affects the band structure and magnetic structure at low temperatures. All calculations indicate mixed metallic-covalent chemi...

Predictions of the BLYP density functional are compared with wavefunction-based calculations for several structural and Ž . q dynamical properties of H O H . We focus attention on properties important for proton transfer in this cluster. Good 2 3 Ž . agreement between density functional theory DFT calculations and all-electron MP2 results is found for energies, structures, and vibrational prope...

Using density functional theory ~DFT! calculations and kinetic simulations, we have investigated the influence of boron atoms on self-interstitial clustering in Si. From DFT calculations of neutral interstitial clusters with a single B atom ~BsIn, n<4!, we find that the binding of B ~BsIn→In21 1BsI) becomes substantially weaker than that of an interstitial ~BsIn→BsIn211I) when n>4. This implies...

Pathways for homogeneous thermal decomposition of (C2H5)3Ga (TEGa) were followed using in situ Raman spectroscopy measurements in an up-flow, cold-wall CVD reactor. The results of Density Functional Theory (DFT) calculations were used to assign measured Raman bands to the decomposition products (Et)3Ga, (DEGa)2, (Et)GaH–Ga(Et)2 and (Et)GaH–GaH2. The results of this study are consistent with bot...

The adsorption of naphthalene tetracarboxylic diimide (NTCDI) on Si(1 1 1)-7 × 7 is investigated through a combination of scanning tunnelling microscopy (STM), noncontact atomic force microscopy (NC-AFM) and density functional theory (DFT) calculations. We show that NTCDI adopts multiple planar adsorption geometries on the Si(1 1 1)-7 × 7 surface which can be imaged with intramolecular bond res...

The IR and Raman spectra of the title compound have been recorded and analyzed. The harmonic vibrational wavenumbers were calculated theoretically using Gaussian09 software package. Calculations were performed by HF and DFT levels using the standard 6-31G* basis sets. The data obtained from vibrational wavenumber calculations are used to assign vibrational bands found in the IR and Raman spectr...

M(N2)n(+) (M = Y, La, Ce; n = 7-8) complexes have been studied by infrared photodissociation (IRPD) spectroscopy and density functional theory (DFT) calculations. The experimental results indicate that the N-N stretching vibrational frequencies are red-shifted from the gas-phase N2 value. The π back-donation is found to be a main contributor in these systems. IRPD spectra and DFT calculations r...

The relative ease of Mössbauer spectroscopy and of density functional theory (DFT) calculations encourages the use of Mössbauer parameters as a validation method for calculations, and the use of calculations as a double check on crystallographic structures. A number of studies have proposed correlations between the computationally determined electron density at the iron nucleus and the observed...

We report the development of a new standard quadrature grid for DFT calculations. Standard Grid 0 (SG-0) is designed to be approximately half as large as, and to provide approximately half the accuracy of, the established SG-1 grid. It is based on MultiExp and Lebedev quadrature for radial and angular coordinates, respectively. We find that SG-0 is typically 50% faster than SG-1 for energy, gra...

The density functional theory (DFT) has become the workhorse in electronic structure calculations. Its success derives from the ability to produce accurate results with reasonable computational effort. The drawback of the DFT is that in principle it is bound to the ground-state properties. However, the time-dependent DFT (TDDFT) extends the applicatibility of the DFT to excited states. In recen...