Pressure-induced spin transition and site-selective metallization in CoCl.

The interplay between spin states and metallization in compressed CoCl is investigated by combining diffraction, resistivity and spectroscopy techniques under high-pressure conditions and ab-initio calculations. A pressure-induced metallization along with a Co high-spin (S = 3/2) to low-spin (S = 1/2) crossover transition is observed at high pressure near 70 GPa. This metallization process, which is associated with the p-d charge-transfer band gap closure, maintains the localization of 3d electrons around Co, demonstrating that metallization and localized Co -3d low-spin magnetism can coexist prior to the full 3d-electron delocalization (Mott-Hubbard d-d breakdown) at pressures greater than 180 GPa.

Unraveling Interactions in Molecular Crystals Using Dispersion Corrected Density Functional Theory: The Case of the Epoxydihydroarsanthrene Molecules.

Noncovalent interactions are prevalent in crystal packing and supramolecular chemistry. Directional noncovalent interactions such as donor-acceptor bonds (e.g.

Topological partition of the elastic constants of crystals.

We present a partitioning of the elastic constants of a crystal into atomic contributions by using the atomic basin concept inherent to Bader's Quantum Theory of Atoms in Molecules. The partition is made by following the evolution of the cell volume and the atomic basin volumes under appropriately defined cell deformations. The method is carefully examined, including internal consistency checks.

Supramolecular architectures based on As(lone pair)···π(aryl) interactions.

As(lone pair)···π interactions provide stability to their crystal structures often leading to supramolecular chains and prevailing over As···X secondary contacts. The interaction (ca 8 kJ mol(-1)) arises from polarisation induced in the aryl ring by the As-lone pair plus the weak sharing of these electrons with the ring-C atoms.

A fast and accurate algorithm for QTAIM integration in solids.

A new algorithm is presented for the calculation of atomic properties, in the sense of the quantum theory of atoms in molecules. This new method, named QTREE, applies to solid-state densities and allows the computation of the atomic properties of all the atoms in the crystal in seconds to minutes. The basis of the method is the recursive subdivision of a symmetry-reduced wedge of the Wigner-Seitz cell, which in turn is expressed as a union of tetrahedra, plus the use of β-spheres to improve the performance.

Topological properties of the electron density of solids and molecules. Recent developments in Oviedo.

Some of the latest advances in the analysis of electron density are reviewed, including: (a) topological indices that provide a useful characterization of the global properties of the density; (b) specific results on some prototypical metal and low heteropolarity systems; and (c) calculation of the local curvature of the interatomic surface.

A classification of covalent, ionic, and metallic solids based on the electron density.

The electron density of crystals contains all of the information required to complete a classification of their bonding types. We propose here a set of three different indexes, flatness, charge transfer, and molecularity, easily obtained from the experimental or theoretical electron density, which give rise to a classification in close resemblance to the classical van Arkel-Ketelaar diagrams.