CANCELLED Molecular dynamics simulations of noble gases in liquidwater: Solvati on structure, self-diffusion, and kinetic isotopeeffect

Bourg, I.C. ; Sposito, G.

关键词: 54;    DIFFUSION;    FRACTIONATION;    GEOCHEMISTRY;    HELIUM;    ISOTOPE EFFECTS;    KINETICS;    KRYPTON;    NEON;    RARE GASES;    SELF-DIFFUSION;    SIMULATION;    SOLVATION;    WATER;    XENON;   

DOI  :  10.2172/929050
RP-ID  :  LBNL--63402
PID  :  OSTI ID: 929050
Others  :  R&D Project: 468208
Others  :  Other: BnR: KC0303020
Others  :  TRN: US200814%%79

美国|英语

来源: SciTech Connect

【 摘 要 】

Despite their great importance in low-temperaturegeochemistry, self-diffusion coefficients of noble gas isotopes in liquidwater (D) have been measured only for the major isotopes of helium, neon,krypton and xenon. Data on the self-diffusion coefficients of minor noblegas isotopes are essentially non-existent and so typically are estimatedby a kinetic theory model in which D varies as the inverse square root ofthe isotopic mass (m): D proportional to m-0.5. To examine the validityof the kinetic theory model, we performed molecular dynamics (MD)simulations of the diffusion of noble gases in ambient liquid water withan accurate set of noble gas-water interaction potentials. Our simulationresults agree with available experimental data on the solvation structureand self-diffusion coefficients of the major noble gas isotopes in liquidwater and reveal for the first time that the isotopic mass-dependence ofall noble gas self-diffusion coefficients has the power-law form Dproportional to m-beta with 0