title: Bonding and structure in dense multi-component molecular mixtures.
abstract: We have performed finite-temperature density functional theory molecular dynamics simulations on dense methane, ammonia, and water mixtures (CH4:NH3:H2O) for various compositions and temperatures (2000 K ≤ T ≤ 10,000 K) that span a set of possible conditions in the interiors of ice-giant exoplanets. The equation-of-state, pair distribution functions, and bond autocorrelation functions (BACF) were used to probe the structure and dynamics of these complex fluids. In particular, an improvement to the choice of the cutoff in the BACF was developed that allowed analysis refinements for density and temperature effects. We note the relative changes in the nature of these systems engendered by variations in the concentration ratios. A basic tenet emerges from all these comparisons that varying the relative amounts of the three heavy components (C,N,O) can effect considerable changes in the nature of the fluid and may in turn have ramifications for the structure and composition of various planetary layers.
authors.affiliation: Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Edmund R
authors.initials: ER
authors.lastname: Meyer
authors.affiliation: Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Christopher
authors.initials: C
authors.lastname: Ticknor
authors.affiliation: Institut für Physik, Universität Rostock, D-18501 Rostock, Germany.
authors.forename: Mandy
authors.initials: M
authors.lastname: Bethkenhagen
authors.affiliation: Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
authors.forename: Sebastien
authors.initials: S
authors.lastname: Hamel
authors.affiliation: Institut für Physik, Universität Rostock, D-18501 Rostock, Germany.
authors.forename: Ronald
authors.initials: R
authors.lastname: Redmer
authors.affiliation: Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Joel D
authors.initials: JD
authors.lastname: Kress
authors.affiliation: Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Lee A
authors.initials: LA
authors.lastname: Collins