Transition-state studies of xenon and SF sub 6 diffusion in silicalite

Journal Article · Thu Oct 31 00:00:00 EST 1991 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100175a083· OSTI ID:7202848

June, R L; Bell, A T; Theodorou, D N ^[1]

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1. Univ. of California, Berkeley (United States)

Self-diffusion coefficients for infinitely dilute spherical sorbate molecules in the zeolite silicalite are computed by transition-state theory. The diffusion process is modeled as a series of uncorrelated jumps between potential minima (sites) determined from a Lennard-Jones representation of the silicalite lattice. Rate constants for jumping between different sites within the lattice are computed by transition-state theory and by the dynamically corrected transition-state theory of Voter and Doll for both a flexible and a rigid zeolite lattice model. Diffusivities are then determined from the rate constants by generating continuous-time/discrete-space Monte Carlo random walks. The computed diffusivities are shown to be in good agreement with molecular dynamics calculations performed on an identical model in the infinite dilution limit at low temperatures and with available experimental results. The transition-state theory and dynamically corrected transition-state theory methods afford computational savings of up to 2 orders of magnitude relative to full molecular dynamics simulations. Shortcomings in the various algorithms and zeolite models are discussed.

• DOE Contract Number: AC03-76SF00098
• OSTI ID: 7202848
• Journal Information: Journal of Physical Chemistry; (United States), Vol. 95:22; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
SULFUR FLUORIDES
SELF-DIFFUSION
XENON
ZEOLITES
SORPTIVE PROPERTIES
ALGORITHMS
COMPUTERIZED SIMULATION
EXPERIMENTAL DATA
KINETICS
MATHEMATICAL MODELS
DATA
DIFFUSION
ELEMENTS
FLUIDS
FLUORIDES
FLUORINE COMPOUNDS
GASES
HALIDES
HALOGEN COMPOUNDS
INFORMATION
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
MATERIALS
MATHEMATICAL LOGIC
MINERALS
NONMETALS
NUMERICAL DATA
RARE GASES
SILICATE MINERALS
SIMULATION
SULFUR COMPOUNDS
SURFACE PROPERTIES
400201* - Chemical & Physicochemical Properties