Kazan, Russian Federation
Although almost 100 years have passed since the publication of the first work devoted to metallic hydrogen, it has still not been obtained experimentally, despite all the efforts of researchers during this period. This hypothetical substance has already been mentioned in a large number of publications - both purely theoretical and related to its experimental synthesis; and each of these works particularly emphasizes the fact that its production requires the application of high pressures to the "precursor", which is hydrogen in a solid state. Moreover, what is quite remarkable is that year after year, the value of the pressure that must be applied to solid hydrogen for its transition to a metallic state shows a clearly expressed tendency to increase: if in the very first work devoted to this unique substance, a pressure of 25 GPa was considered sufficient for its synthesis, now we are talking about the need to apply pressures an order of magnitude greater than this value - i.e. hundreds of GPa (and, accordingly, millions of atmospheres). Given the numerous failed attempts to produce metallic hydrogen, there's every reason to ask a simple question: is its existence even possible, even though quantum chemical calculations suggest it. This article addresses these doubts about the possibility of such a substance.
METALLIC HYDROGEN, HIGH PRESSURE, SYNTHESIS, MOLECULAR STRUCTURE, QUANTUM-CHEMICAL CONSIDERATION
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