The encapsulation of metal atoms within Si-based cage clusters leads to stable metal-encapsulated Si cage clusters (Si-cc). The present work investigates the effect of encapsulation of transition metal atoms (TMAs). We show that the filling factor of the d-band of the TMA is the dominant factor determining the structural configuration of the Si-cc. This results in a contrasting bonding and magn...

We present a density-functional-theory study of transition-metal atoms (Sc-Zn, Pt, and Au) embedded in single and double vacancies (SV and DV) in a graphene sheet. We show that for most metals, the bonding is strong and the metal-vacancy complexes exhibit interesting magnetic behavior. In particular, an Fe atom on a SV is not magnetic, while the Fe@DV complex has a high magnetic moment. Surpris...

A linear response time-dependent density functional theory is described and used to calculate the dynamic polarizabilities and van der Waals C(6) coefficients of complex atom pairs. We present values of C(6) for dimers of main group atoms and the first row of transition metal atoms.

Many enzymes use metal ions within their active sites to achieve enormous rate acceleration. Understanding how metal ions mediate catalysis requires elucidation of metal ion interactions with both the enzyme and the substrate(s). The three-dimensional arrangement determined by X-ray crystallography provides a powerful starting point for identifying ground state interactions, but only functional...

This study examines structural variations found in the atomic ordering of different transition metal nanoparticles synthesized via a common, kinetically controlled protocol: reduction of an aqueous solution of metal precursor salt(s) with NaBH₄ at 273 K in the presence of a capping polymer ligand. These noble metal nanoparticles were characterized at the atomic scale using spherical aberration-...

Extensive LAPW frozen phonon calculations were performed in order to understand the origin of ferroelectricity in LiTaO3 and LiNbO3. Displacement of the Li atoms alone results in an anharmonic single well, whereas displacements of oxygen and lithium together result in deep double wells, much deeper than the transition temperatures, TC . This is contrary to current theories which model the under...

Positions and anisotropic thermal motion of H-Atoms bound to heavy atoms in transition-metal hydride complexes were successfully refined using Hirshfeld Atom Refinement (HAR) against low resolution X-ray diffraction data.

The Chevrel type chalcogenide with the stoichiometry Mo6.,M,Xs (M=transition metal, e.g., M,=Ru2; X=Chalcogene atom, e.g., S, Se) containing octahedral mixed-metal clusters of transition-metal atoms was investigated with respect to the oxygen reduction process in an in situ electrochemical enviroment via the EXAFS technique. The spectra analysis on Ru and MO edges as a function of applied elect...

The 5d transition metal oxide Cd2Os2O7 having a pyrochlore lattice of Os atoms exhibits a metal-insulator transition with a magnetic ordering at 227 K, but the magnetic structure in the ordered state and the origin of the transition have not yet been specified. The commensurate magnetic reflection with the propagation vector k = (0, 0, 0) was first observed in the resonant X-ray scattering usin...

The electrochemical properties of diazophenylcalix[4]arenes bearing ortho-carboxyl group (o-CAC) and ortho-ester group (o-EAC), respectively, in the presence of various metal ions were investigated by voltammetry in CH3CN. o-CAC and o-EAC showed voltammetric changes toward divalent metal ions and no significant changes with monovalent alkali metal ions. However, o-CAC preferentially binds with ...