Guenter Schneider

FLAPW: applications and implementations.

Modern material design involves a close collaboration between experimental and computational materials scientists. To be useful, the theory must be able to accurately predict the stability and properties of new materials, describe the physics of the experiments, and be applicable to new and complex structures-the all-electron full-potential linearized augmented plane wave (FLAPW) is one such method that provides the requisite level of numerical accuracy, albeit at the cost of complexity. Technical aspects and modifications related to the choice of basis functions (energy parameters, core-valence orthogonality, extended local orbitals) that affect the applicability and accuracy of the method are described, as well as an approach for obtaining k-independent matrix elements. The inclusion of external electric fields is illustrated by results for the induced densities at the surfaces of both magnetic and non-magnetic metals, and the relationship to image planes and to nonlinear effects such as second harmonic generation. The magnetic coupling of core hole excitations in Fe, the calculation of intrinsic defect formation energies, the concentration-dependent chemical potentials, entropic contributions, and the relative phase stability of Zr-rich Zr-Al alloys are also discussed.

Electronic and optical properties of potential solar absorber Cu3PSe4

We theoretically investigate the electronic and optical properties of semiconductor Cu3PSe4. We also report diffuse reflectance spectroscopy measurements for Cu3PSe4 and Cu3PS4, which indicate a band gap of 1.40 eV for the former. Ab initio density functional theory (DFT) calculations based on hybrid functionals agree well with this value and reveal that the band gap is direct. Calculations yield an optical absorption spectrum similar to GaAs in the visible region, with α > 5 × 104 cm−1 for λ < 630 nm. We conclude that the optical properties of Cu3PSe4 are within the desired range for a photovoltaic solar absorber material.

Defect physics of BaCuChF (Ch=S, Se, Te) p-type transparent conductors

This is the publisher’s final pdf. The published article is copyrighted by The American Physical Society and can be found at: http://prb.aps.org/.

Mechanical Reversibility of Strain-Promoted Azide-Alkyne Cycloaddition Reactions

Mechanophores, that is, molecules that show a defined response to force, are crucial building blocks of mechanoresponsive materials. The possibility of mechanically induced cycloreversion for a series of triazoles formed via strain-promoted azide-alkyne cycloaddition reactions was investigated by density functional theory calculations, and these triazoles were compared to the 1,4- and 1,5-regioisomers formed in the reaction of an azide with a terminal alkyne. We show that cycloreversion is in principal possible and that the pulling geometry is the most important parameter that determines the probability of cycloreversion. We further compared triazole stability to the mechanical stability of polymers that are frequently used as force transducers in mechanochemical experiments and identified DIBAC (azadibenzylcyclooctyne) as a promising mechanophore for future applications.

Lowering of surface melting temperature in atomic clusters with a nearly closed shell structure

We investigate the interplay of particle number,

Modeling the Electrostatic Signature of Single Enzyme Activity

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Shell model of BaTiO3 derived from ab-initio total energy calculations

, and structural properties of selected clusters with

Defect physics and electronic properties of Cu₃PSe₄ from first principles

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Multiscale modeling of solar cells with interface phenomena

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Role of orbital polarization in calculations of the magnetic anisotropy

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