论文标题
在压力和对巨型行星的影响下，C-H-N-O系统的异常化学反应
Unusual chemistry of the C-H-N-O system under pressure and implications for giant planets
论文作者
论文摘要
C-H-N-O系统对于有机化学和生物化学是核心，并且在行星科学（主导“冰巨人”天王星和海王星的组成）中起着重要作用。该系统在正常条件下的无尽化学多样性将其解释为所有已知生命的基础，但是该系统在高压和行星内部温度下的化学反应是众所周知的。 Using ab initio evolutionary algorithm USPEX, we performed an extensive study of the phase diagram of the C-H-N-O system at pressures of 50, 200, and 400 GPa and temperatures up to 3000 K. Eight novel thermodynamically stable phases were predicted, including quaternary polymeric crystal C2H2N2O2 and several new N-O and H-N-O compounds.我们描述了在压力下C-H-N-O系统化学变化的主要模式，并确认应在天王星和海王星的中冰层的条件下形成钻石。我们还提供了高压的详细CH4-NH3-H2O相图，这对于进一步改善冰巨头模型很重要，并指出当前模型显然是不足的。 In particular, in existing models Uranus and Neptune are presented to have identical composition, nearly identical pressure-temperature profiles, and a single convecting middle layer ("mantle") made of a mixture H2O : CH4 : NH3 = 56.5 : 32.5 : 11. Here we provide new insights shedding light into the difference of heat flows from Uranus and Neptune, which require them to have different compositions, pressure-temperature条件和更复杂的内部结构。
C-H-N-O system is central for organic chemistry and biochemistry, and plays a major role in planetary science (dominating the composition of "ice giants" Uranus and Neptune). The inexhaustible chemical diversity of this system at normal conditions explains it as the basis of all known life, but the chemistry of this system at high pressures and temperatures of planetary interiors is poorly known. Using ab initio evolutionary algorithm USPEX, we performed an extensive study of the phase diagram of the C-H-N-O system at pressures of 50, 200, and 400 GPa and temperatures up to 3000 K. Eight novel thermodynamically stable phases were predicted, including quaternary polymeric crystal C2H2N2O2 and several new N-O and H-N-O compounds. We describe the main patterns of changes in the chemistry of the C-H-N-O system under pressure and confirm that diamond should be formed at conditions of the middle-ice layers of Uranus and Neptune. We also provide the detailed CH4-NH3-H2O phase diagrams at high pressures, which are important for a further improvement of the models of ice giants - and point out that current models are clearly deficient. In particular, in existing models Uranus and Neptune are presented to have identical composition, nearly identical pressure-temperature profiles, and a single convecting middle layer ("mantle") made of a mixture H2O : CH4 : NH3 = 56.5 : 32.5 : 11. Here we provide new insights shedding light into the difference of heat flows from Uranus and Neptune, which require them to have different compositions, pressure-temperature conditions, and a more complex internal structure.
