Calculated Diffusivities for Water Isotopologues in Carbon Dioxide, Nitrogen, and the Atmosphere of Mars, and for Methane Isotopologues in Nitrogen Representing the Atmosphere of Titan

Values are computed for the dilute-gas diffusivity of water isotopologues in N2, CO2, and their mixture at a composition representing the atmosphere of Mars, for standard conditions of 101.325 kPa and water mole fraction approaching zero. Values are similarly computed for the diffusivity of methane isotopologues in N2, representing the atmosphere of Titan. Calculations employ state-of-the-art intermolecular potentials and classical trajectory calculations as described in the paper by R. Hellmann and A.H. Harvey, "First-Principles Diffusivity Ratios for Atmospheric Isotope Fractionation on Mars and Titan", published in Journal of Geophysical Research: Planets, 126, e2021JE006857 (2021), https://doi.org/10.1029/2021JE006857. Separate files are given for the diffusivities of H2O, HDO (where D is deuterium), and the 17-O and 18-O substitutions of H2O, and for the diffusivities in N2 of CH4, CH3D, and the 13-C substitution of CH4.

[
  "006:55"
]

[
  "en"
]

[
  "006:045"
]

[
  "Chemistry:Chemical thermodynamics and chemical properties",
  "Chemistry:Theoretical chemistry and modeling",
  "Physics:Atomic, molecular, and quantum"
]