Effect of coordination of protons and cations on the geometric characteristics of zeolites
Journal Article
·
· J. Phys. Chem.; (United States)
The nonempirical SCF method with the STO-3G basis set is used to study the effect of the coordination of protons and Li or Na cations to the >SiOAl< fragments in zeolites on their geometric characteristics. The >SiOAl< fragments are represented by the H/sub 3/SiOAlH/sub 3//sup -/ and H/sub 3/SiOXAlH/sub 3/ molecular systems (X = H, Li, and Na). The rigidity of the lattice is modeled by maintaining the terminal H atoms in different positions while the positions of the remaining atoms are optimized. It is shown that, independent of these model structural limitations, the geometric characteristics of the >SiOXAl< fragments (particularly their SiO and AlO bond lengths) differ very little from the equilibrium values, indicating that the fragment geometry is determined primarily by internal interactions within the fragments. The extent of changes in the geometry of the >SiOAl< fragment resulting from the coordination of individual ions is correlated with their electronegativity and exhibits the following trend: H > Li > Na.
- Research Organization:
- J. Heyrovsky Institute of Physical Chemistry and Electrochemistry, Prague (Czechoslovakia)
- OSTI ID:
- 5388079
- Journal Information:
- J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 92:3; ISSN JPCHA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
07 ISOTOPE AND RADIATION SOURCES
070100 -- Physical Isotope Separation
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKALI METAL COMPOUNDS
ALUMINIUM COMPOUNDS
ALUMINIUM SILICATES
BOND ANGLE
BOND LENGTHS
CATIONS
CHARGED PARTICLES
COMPUTER CALCULATIONS
COMPUTER CODES
COORDINATION NUMBER
COORDINATION VALENCES
DATA
DIMENSIONS
G CODES
HYDROGEN COMPOUNDS
INFORMATION
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
IONS
LENGTH
LITHIUM COMPOUNDS
MATERIALS
MATHEMATICAL MODELS
MINERALS
MOLECULAR MODELS
NUMERICAL DATA
OXYGEN COMPOUNDS
SELF-CONSISTENT FIELD
SILICATES
SILICON COMPOUNDS
SODIUM COMPOUNDS
STRUCTURAL CHEMICAL ANALYSIS
THEORETICAL DATA
VALENCE
ZEOLITES
070100 -- Physical Isotope Separation
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKALI METAL COMPOUNDS
ALUMINIUM COMPOUNDS
ALUMINIUM SILICATES
BOND ANGLE
BOND LENGTHS
CATIONS
CHARGED PARTICLES
COMPUTER CALCULATIONS
COMPUTER CODES
COORDINATION NUMBER
COORDINATION VALENCES
DATA
DIMENSIONS
G CODES
HYDROGEN COMPOUNDS
INFORMATION
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
IONS
LENGTH
LITHIUM COMPOUNDS
MATERIALS
MATHEMATICAL MODELS
MINERALS
MOLECULAR MODELS
NUMERICAL DATA
OXYGEN COMPOUNDS
SELF-CONSISTENT FIELD
SILICATES
SILICON COMPOUNDS
SODIUM COMPOUNDS
STRUCTURAL CHEMICAL ANALYSIS
THEORETICAL DATA
VALENCE
ZEOLITES