Transition-state studies of xenon and SF sub 6 diffusion in silicalite
- 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), Journal Name: Journal of Physical Chemistry; (United States) Vol. 95:22; ISSN 0022-3654; ISSN JPCHA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Molecular dynamics studies on zeolites. 6. Temperature dependence of diffusion of methane in silicalite
Classically exact surface diffusion constants at arbitrary temperature
Related Subjects
400201* -- Chemical & Physicochemical Properties
ALGORITHMS
COMPUTERIZED SIMULATION
DATA
DIFFUSION
ELEMENTS
EXPERIMENTAL DATA
FLUIDS
FLUORIDES
FLUORINE COMPOUNDS
GASES
HALIDES
HALOGEN COMPOUNDS
INFORMATION
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
KINETICS
MATERIALS
MATHEMATICAL LOGIC
MATHEMATICAL MODELS
MINERALS
NONMETALS
NUMERICAL DATA
RARE GASES
SELF-DIFFUSION
SILICATE MINERALS
SIMULATION
SORPTIVE PROPERTIES
SULFUR COMPOUNDS
SULFUR FLUORIDES
SURFACE PROPERTIES
XENON
ZEOLITES