Compressive behavior and electronic properties of ammonia ice: a first-principles study

Abstract

We performed systematic ab initio calculations to explore the structures and electronic properties of ammonia ice by hydrostatic compression.

Stabilisation of solid-state cubic ammonia confined in a glass substance at ambient temperature under atmospheric pressure

“…The triple point of NH 3 is characterised by specic temperature (195.5 K) and pressure (0.0609 bar) values. [11][12][13][14][15][16][17][18][19] Below 195.5 K and at pressures exceeding 0.0609 bar, NH 3 exists in its solidstate cubic form. 24,25 Given this, achieving the stabilisation of solid-state cubic-NH 3 (cr) at ambient temperature and atmospheric pressure presents signicant challenges.…”

“…Initially, the Gibbs energy of formation, D f G m , for NH 3 (g) at 195.5 K under 0.0609 bar-representing the temperature and pressure of the triple point-was calculated. [11][12][13][14][15][16][17][18][19] Given that NH 3 (cr) is equilibrated with NH 3 (g) at the triple point, the D f G m datum of NH 3 (cr) equals that of NH 3 (g). Subsequently, the D f G m datum at 298.15 K under 1 bar for cubic NH 3 (cr) was estimated.…”

“…[5][6][7][8][9][10] The foundational understanding of ammonia spans disciplines such as space exploration, life sciences, material engineering, and environmental studies, primarily revolving around its stability across different phases: solid, liquid, and gas. [11][12][13][14][15][16][17][18][19] Pressure-temperature diagrams detailing these phases have been meticulously constructed, underscoring the versatile nature of ammonia. For instance, its triple point, occurring at 195.5 K and 0.0609 bar, highlights the stability of its gas phase even at ambient temperatures under atmospheric pressure.…”

“…This breakthrough opens avenues for further exploration at the forefronts of diverse scientic domains, hinting at promising implications and applications of cubic ammonia. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] Shiing perspectives towards utilising ammonia as a hydrogen storage material prompts consideration of the challenges associated with its storage and transport due to its harmful effects on human health. These effects encompass potential eye damage upon contact, respiratory distress upon inhalation, and the risk of impaired consciousness due to elevated blood ammonia levels, which can prove fatal in severe cases.…”

“…This breakthrough opens avenues for further exploration at the forefronts of diverse scientific domains, hinting at promising implications and applications of cubic ammonia. 1–19…”