Axial ratio of Zn at high pressure and low temperature

Abstract

High-pressure powder x-ray-diffraction experiments have been carried out on Zn with a He-pressure medium up to 18 GPa at 40 K. No anomaly in the volume dependence of the c/a axial ratio has been found within experimental errors. The c/a anomaly, which has been predicted to appear associated with the electronic topological transitions, should be extremely small. Thermal expansion of Zn rapidly decreases under high pressure, yielding nearly identical axial ratios at room and low temperatures.

Synthesis of a Nitrogen-Stabilized Hexagonal Re3ZnNx Phase Using High Pressures and Temperatures

“…Ambient Re and Zn have metallic radii within 2.6% of each other, they have the same crystal structure ( P 6 3 / mmc ), but their electronegativities differ by about 15% and their conventional most stable valencies are +6 or +7 and +2, respectively. , In addition to this, we point at the anomalously large for an hcp metal c/a ratio (1.87) for Zn at ambient pressure, attributed to a lowering of band structure energy through lattice distortion, which may bear on solid solution formation. However, while the anomalous c/a ratio of Zn, at and above 20 GPa, becomes typical of hexagonal structures (1.68), and the atomic radii of Re and Zn are within 4% at 20 GPa, and both Re and Zn retain the P 6 3 / mmc structure, ,,− the elements still do not react. This is the case, even though their melting points are also converging to within a factor of about 2 of each other at 20 GPa, rather than 7 at ambient pressure .…”

“…Rhenium has a normal c/a lattice constant ratio of 1.61 which remains normal to over 2 million atmospheres . Zinc on the other hand is highly anisotropic, with a c/a ratio of 1.86 which becomes more normal upon compression, reaching a value of about 1.67 at 20 GPa . Indeed Zn is the focus of intense interest in correlating how the underlying electronic structure transforms with the change in anisotropy.…”

Stability and equation of state of face-centered cubic and hexagonal close packed phases of argon under pressure

“…In the literature, cases where non-hydrostatic stress affect the measured EoS have been discussed, such as systematic bias 16 , 19 , 20 , unphysical lattice distortions 17 , 18 . This stress should thus be evaluated here in order to discuss argon EoS.…”

Kenichi Fukui, Frontier Molecular Orbital Theory, and the Woodward‐Hoffmann Rules. Part III. Fukui's Science and Technology, 1918–1965†**

“…aaa. June 2, 1962: Molecular Orbital Interpretation of Some Physicochemical Properties of Alkyl Compounds [276] Yonezawa, Kato, Saito, and Fukui applied Fukui's LCAO MO treatment for saturated compounds [237,239,250,267] to calculate electronic structures, n-σ* absorption energies, PQR coupling constants, proton NMR shielding constants, and electron distributions in mono-, di-, tri-, and tetraiodomethanes.…”

“…An act of omission may be harder to understand than an act of selection. [239] In this continuation of their calculations on saturated hydrocarbons [237,239,250] using the Yoshizumi method, [238] Fukui, [253] Structures in the left column are added by the present author for ease in understanding the structural variations among the data set. It is noteworthy that a simple visual mnemonic exists for these compounds: that of retaining maximum aromatic stabilization, with the least benefit being obtained by the furthest condensed aromatic ring.…”