Liquid methane at extreme temperature and pressure: Implications for models of Uranus and Neptune

Abstract

We present large scale electronic structure based molecular dynamics simulations of liquid methane at planetary conditions. In particular, we address the controversy of whether or not the interior of Uranus and Neptune consists of diamond. In our simulations we find no evidence for the formation of diamond, but rather sp2-bonded polymeric carbon. Furthermore, we predict that at high tem- perature hydrogen may exist in its monoatomic and metallic state. The implications of our finding for the planetary models of Uranus and Neptune are in detail discussed.

4 pages, 3 figures

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• An Efficient and Accurate Car-Parrinello-like Approach to Born-Oppenheimer Molecular Dynamics
• State-of-the-art models for the phase diagram of carbon and diamond nucleation
• An efficient and accurate decomposition of the Fermi operator

Cited by in corpus (5)

• CP2K: An Electronic Structure and Molecular Dynamics Software Package -- Quickstep: Efficient and Accurate Electronic Structure Calculations
• Recent achievements in ab initio modelling of liquid water
• Self-consistent field theory based molecular dynamics with linear system-size scaling
• On the optimal calculation of the pair correlation function for an orthorombic system
• Distributed Charge Models of Liquid Methane and Ethane for Dielectric Effects and Solvation