Path integral Monte Carlo simulations of dense carbon-hydrogen plasmas

Abstract

Carbon-hydrogen plasmas and hydrocarbon materials are of broad interest to laser shock experimentalists, high energy density physicists, and astrophysicists. Accurate equations of state (EOS) of hydrocarbons are valuable for various studies from inertial confinement fusion (ICF) to planetary science. By combining path integral Monte Carlo (PIMC) results at high temperatures and density functional theory molecular dynamics (DFT-MD) results at lower temperatures, we compute the EOS for hydrocarbons at 1473 separate ($\rho ,T$)-points distributed over a range of compositions. These methods accurately treat electronic excitation and many-body interaction effects and thus provide a benchmark-quality EOS that surpasses that of semi-empirical and Thomas-Fermi-based methods in the warm dense matter regime. By comparing our first-principles EOS to the LEOS 5112 model for CH, we validate the specific heat assumptions in this model but suggest that the Grueneisen parameter is too large at low temperature. Based on our first-principles EOS, we predict the Hugoniot curve of polystyrene to be 2-5% softer at maximum compression than that predicted by orbital-free DFT and SESAME 7593. By investigating the atomic structure and chemical bonding, we show a drastic decrease in the lifetime of chemical bonds in the pressure interval of 0.4-4 megabar. We find the assumption of linear mixing to be valid for describing the EOS and the shock Hugoniot curve of the dense, partially ionized hydrocarbons under consideration. We make predictions of the shock compression of glow-discharge polymers and investigate the effects of oxygen content and C:H ratio on their Hugoniot curve. Our full suite of first-principles simulation results may be used to benchmark future theoretical investigations pertaining to hydrocarbon EOS, and should be helpful in guiding the design of future gigabar experiments.

arXiv comment14 pages, 13 figures, 1 table;

References in corpus (40)

• Phonons and related properties of extended systems from density-functional perturbation theory
• The Interiors of Giant Planets: Models and Outstanding Questions
• Nuclear quantum effects in water
• Lattice anharmonicity and thermal conductivity from compressive sensing of first-principles calculations
• Path Integral Monte Carlo Calculation of the Deuterium Hugoniot
• FPEOS: A First-Principles Equation of State Table of Deuterium for Inertial Confinement Fusion Applications
• Molecular Dissociation in Hot, Dense Hydrogen
• Hydrogen-Helium Mixtures in the Interiors of Giant Planets
• Nuclear Quantum Effects and Nonlocal Exchange-Correlation Functionals Applied to Liquid Hydrogen at High Pressure
• A multiphase equation of state for carbon addressing high pressures and temperatures
• Simulation and understanding of quantum crystals
• All-Electron Path Integral Monte Carlo Simulations of Warm Dense Matter: Application to Water and Carbon Plasmas
• Path Integral Monte Carlo Simulation of the Low-Density Hydrogen Plasma
• Rocky core solubility in Jupiter and giant exoplanets
• Anomalous Nuclear Quantum Effects in Ice
• Sequestration of noble gases in giant planet interiors
• Superionic to superionic phase change in water: consequences for the interiors of Uranus and Neptune
• First Principles Calculations of Shock Compressed Fluid Helium
• Path Integral Monte Carlo and Density Functional Molecular Dynamics Simulations of Hot, Dense Helium
• Calculation of a Deuterium Double Shock Hugoniot from Ab initio Simulations
• Extended First-Principles Molecular Dynamics Method From Cold Materials to Hot Dense Plasmas
• Towards a Predictive First-Principles Description of Solid Molecular Hydrogen with Density-Functional Theory
• First-Principles Equation of State Calculations of Warm Dense Nitrogen
• High-temperature miscibility of iron and rock during terrestrial planet formation
• The Coupled Electron-Ion Monte Carlo Method
• A path-integral molecular dynamics simulation of diamond
• First-Principles Equation of State and Electronic Properties of Warm Dense Oxygen
• First-principles Equation of State and Shock Compression Predictions of Warm Dense Hydrocarbons
• Simulations of Dense Atomic Hydrogen in the Wigner Crystal Phase
• High-pressure, temperature elasticity of Fe- and Al-bearing MgSiO3: implications for the Earth's lower mantle
• First-Principles Prediction of the Softening of the Silicon Shock Hugoniot Curve
• Ab Initio Simulations of Hot, Dense Methane During Shock Experiments
• Properties of hydrogen, helium, and silicon dioxide mixtures in giant planet interiors
• An ab initio path integral Monte Carlo simulation method for molecules and clusters: application to Li_4 and Li_5^+
• Characterization of the State of Hydrogen
• Thermophysical properties for shock compressed polystyrene
• Equation of state and shock compression of warm dense sodium - a first-principles study
• First-Principles Simulations of Warm Dense Lithium Fluoride
• Hydrogen-Helium Mixtures at High Pressure
• Revealing the Complex Transport Behaviors in Warm Dense Hydrogen by Including Nuclear Quantum Effects

Cited by in corpus (13)

• First-Principles Equation of State Database for Warm Dense Matter Computation
• Electronic Density Response of Warm Dense Matter
• Ab initio path integral Monte Carlo approach to the momentum distribution of the uniform electron gas at finite temperature without fixed nodes
• Equation of state of warm-dense boron nitride combining computation, modeling, and experiment
• Path Integral Monte Carlo and Density Functional Molecular Dynamics Simulations of Warm, Dense MgSiO${}_3$
• Theoretical and experimental investigation of the equation of state of boron plasmas
• Magnesium Oxide at Extreme Temperatures and Pressures Studied with First-Principles Simulations
• Benchmarking boron carbide equation of state using computation and experiment
• Transferable Interatomic Potentials for Aluminum from Ambient Conditions to Warm Dense Matter
• Thermal and Pressure Ionization in Warm, Dense MgSiO${}_3$ Studied with First-Principles Computer Simulations
• Comparison of ablators for the polar direct drive exploding pusher platform
• Nature of the bonded-to-atomic transition in liquid silica to TPa pressures
• First-principles Equations of State and Structures of Liquid Metals in Multi-megabar Conditions