The configuration-interaction CI method is applied to the calculation of the structures of a number of positron binding systems, including e+Be, e+Mg, e+Ca, and e+Sr. These calculations were carried out in orbital spaces containing about 200 electron and 200 positron orbitals up to =12. Despite the very large dimensions, the binding energy and annihilation rate converge slowly with , and the fi...

The title compound, C(9)H(8)N(4)S·C(3)H(7)NO, adopts an E configuration about both the C=N and C-N bonds. Inter-molecular N-H⋯O hydrogen bonding links the compound to the DMF solvent molecule. The crystal packing is characterized by chains of mol-ecules linked by inter-molecular N-H⋯S hydrogen-bonding inter-actions.

The title mol-ecule, C(12)H(14)N(2)O(4), adopts a trans configuration with respect to the C=N double bond. The amino group is involved in an intra-molecular N-H⋯O hydrogen bond. In the crystal structure, inter-molecular O-H⋯O hydrogen bonds link the mol-ecules into doubled sheets parallel to the (101) plane.

The first representative of a possible new class of conjugated cyclic polyacetylenes is predicted using DFT calculations. These species have a helical secondary structure and a closed-shell electronic ground-state configuration. Molecular and spectroscopic properties are discussed, and a distinct anapolar ring current structure in a constant and homogeneous magnetic field, perpendicular to the ...

We study a model of multi-legged catalytic molecular walkers that abstract a class of recently developed synthetic molecular motors. We focus on their kinetics of release of catalytic product, delineating the influence of chemical kinetic parameters, geometric configuration, loss from surface, and bulk kinetics. We show that such walkers can achieve a uniform rate of release over long time scal...

The C=C double bond in the title compound, C(18)H(15)BrO(4), adopts an E configuration. The two rings are almost orthogonal to each other, making a dihedral angle of 82.8 (1)°. An intra-molecular C-H⋯O hydrogen bond occurs. The crystal structure is stabilized by inter-molecular C-H⋯O hydrogen bonds.

creating and preserving large patches in land use configuration and satisfying compactness and contiguity in land use configuration are nature-prescribed and nature-inspired criteria that can be used in land use planning better that before. accompanying compactness and contiguity as the important landscape metrics in land use planning and land use configuration is close to applying proactive ap...

This Special Issue of Chemistry is dedicated to Dr. Howard D. Flack (1943–2017), a renowned crystallographer who transformed the way in which, by using single crystal X-ray diffraction, we are able determine absolute structure crystalline material, and thereby configuration molecular species within material [...]