Ionic radii for Group 1 and Group 2 halide, hydride, fluoride, oxide, sulfide, selenide and telluride crystals

Abstract

This paper discusses the calculation of internuclear distances by a soft-sphere ionic radii model for twenty crystalline Group 1 halides and hydrides and three ammonium halides with either sodium chloride or caesium chloride structures. It also describes calculation of internuclear distances with the soft-sphere model for three crystalline Group 2 fluorides with fluorite structures and fifteen Group 2 crystalline binary salts (oxides, sulfides, selenides and tellurides) with sodium chloride structures. Soft-sphere calculated radii for Group 1 salts are compared with other theoretical radii. Soft-sphere calculated results agree very well with experimental measurements in all cases except for lithium hydride. The probable reasons for the discrepancy with lithium hydride and merits of the soft sphere model are discussed. A simple expression to calculate lattice energies using the soft-sphere radii concept is given and results compared well with lattice energies calculated by the Born-Haber cycle.

Pure H – conduction in oxyhydrides

“…The conduction of hydride ions, H -, is also attractive. These are similar in size to oxide and fluoride ions (6) and show strong reducing properties with a standard redox potential of H -/H 2 (-2.3 V), which is close to that of Mg/Mg 2+ (-2.4 V). Hydride ion conductors may therefore be applied in energy storage and conversion devices with high energy densities.…”

Structural Studies of Medicago truncatula Histidinol Phosphate Phosphatase from Inositol Monophosphatase Superfamily Reveal Details of Penultimate Step of Histidine Biosynthesis in Plants

“…Those two aspartates coordinate a magnesium cation (at 0.7 occupancy) in the HOLP complex structure. The presence of Mg 2ϩ cation was concluded based on O-Mg 2ϩ distances that refined to 2.11 Ϯ 0.07 Å (eight distances in four protein subunits were taken into account), which is very close to the ideal value of 2.107 (60). Those distances are certainly too short for a hydrogen bond involving a water molecule (Ն2.…”

Inkjet Printing of Li‐Rich Cathode Material for Thin‐Film Lithium‐Ion Microbatteries

“…The lattice parameters and the size of the coherent scattering region (CSR) are shown in Table . With the introduction of alkaline metals, an increase in the lattice parameter a and cell volume is observed due to a larger ionic radius (Li < Na < K) when compared with a pure LMR sample . Presumably, it broadens the lithium diffusion channels.…”

“…Replacing Co atoms with Al atoms reduces the unit cell size along the a axis due to different ionic radii of these elements (Al 3+ = 0.0535 nm versus Co 3+ = 0.061 nm) . Similarly, the replacement of Li ions with Na and K ions increases the volume of the cell unit, due to larger ionic radii, thereby expanding the diffusion channels of lithium causing, presumably, an increase in the diffusion rate of lithium ions.…”