Mekhanobr Engineering JSC (Russia):

Zuev V. V., Doctor of Geology and Mineralogy, Leading Researcher, science@mekhanobr.spb.ru

The publication continues the author’s series of papers on the problem of studying nature and properties of mineral substances, corresponding to the extreme P-T conditions of their formation in the central zones of Earth and also other planets. Metallic hydrogen is one of such substances, and scant information is available about it in the literature, this paper challenging this lack of knowledge. A probable structure, properties and conditions of formation of hydrogen metallic phase are considered in the paper. On the basis of the atom kernels and binding electrons crystal chemistry, developed by the author, a body-centered cubic lattice structure with elementary cell parameter a₀ = 1.016 Å, density ρ = 3.17 g/cm³, hardness, close to that of diamond, conditions of formation Р = 3000 GPa and thermodynamic stability T_melting = 6500 K are assumed in the paper. This melting temperature seems to be a relatively low value, if extremely high pressure of metallic hydrogen formation is taken into consideration. Hydrogen kernel ionic radius is calculated to be r_i(H¹⁺) = 0.15 Å, and its variation is determined with respect to coordination. The Earth’s inner core hydride hypothesis is subjected to criticism in favor of the hypothesis of the Earth’s inner core composition from Fe-Co-Ni elements in hypervalent states.

1. Zuev V. V. Konstitutsiya, svoystva mineralov i stroyeniye Zemli (energeticheskiye aspekty) (Constitution, properties of minerals and Earth structure (power aspects)). St. Petersburg, Nauka, 2005, 402 p.
2. Zuyev V. Ostovno-elektronnaya kristallokhimiya i svoystva mineralov (s ispolzovaniyem additivnoy geoenergeticheskoy kontseptsii Fersmana) (Atom kernels and binding electrons crystal chemistry and properties of minerals (with use of Fersman's additive geopower conception)). Germany, Lambert Academic Publishing, 2012, 324 p.
3. Emsley J. Elementy (The Elements). Moscow, Mir, 1993, 256 p.
4. Volkov A. I., Zharskiy I. M. Bolshoy khimicheskiy spravochnik (Large chemical reference). Minsk, Sovremennaya shkola, 2005, 608 p.
5. Batsanov S. S. Eksperimentalnyye osnovy strukturnoy khimii (Experimental basis of structural chemistry). Moscow, Izdatelstvo standartov, 1986, 240 p.
6. Povarennykh A. S. Tverdost' mineralov (Hardness of minerals). Kiev, Academy of Sciences of the Ukrainian SSR, 1963, 304 p.
7. Zuev V. V. Energoplotnost', svoystva mineralov i energeticheskoye stroyeniye Zemli (Power density, properties of minerals and energy structure of the Earth). St. Petersburg, Nauka, 1995, 128 p.
8. Larin V. N. Nasha Zemlya (Our Earth). Moscow, Agar, 2005, 248 p.
9. Zuev V. V. Provision of an energy rationale for the hypothesis of the Earth's inner core three-phase composition from Fe–Co–Ni elements in hypervalent states. Obogashchenie Rud, 2014, No. 1, pp. 34–38.