Theoretical study of the structure, energetics, and dynamics of silicon and carbon systems using tight-binding approaches
Semiempirical interatomic potentials are developed for silicon and carbon by modeling the total energy of the system using tight-binding approaches. The parameters of the models were obtained by fitting to results from accurate first-principles Local Density Functional calculations. Applications to the computation of phonons as a function of volume for diamond-structured silicon and carbon and the thermal expansions for silicon and diamond yields results which agree well with experiment. The physical origin of the negative thermal expansion observed in silicon is explained. A tight-binding total energy model is generated capable of describing carbon systems with a variety of atomic coordinations and topologies. The model reproduces the total energy versus volume curves of various carbon polytypes as well as phonons and elastic constants of diamond and graphite. The model has also been used in the molecular-dynamics simulation of the properties of carbon clusters. The calculated ground-state geometries of small clusters (C{sub 2}--C{sub 10}) correlates well with results from accurate quantum chemical calculations, and the structural trend of clusters from C{sub 2} to C{sub 60} are investigated. 67 refs., 19 figs.
- Research Organization:
- Ames Lab., Ames, IA (United States)
- Sponsoring Organization:
- USDOE; USDOE, Washington, DC (United States)
- DOE Contract Number:
- W-7405-ENG-82
- OSTI ID:
- 5073116
- Report Number(s):
- IS-T-1583; ON: DE92002695
- Resource Relation:
- Other Information: Thesis (Ph.D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CARBON
BINDING ENERGY
INTERATOMIC FORCES
DIAMONDS
THERMAL EXPANSION
SILICON
DYNAMICS
ELECTRONIC STRUCTURE
INTERATOMIC DISTANCES
PHONONS
SOLID CLUSTERS
DISTANCE
ELEMENTAL MINERALS
ELEMENTS
ENERGY
EXPANSION
MECHANICS
MINERALS
NONMETALS
QUASI PARTICLES
SEMIMETALS
640302* - Atomic
Molecular & Chemical Physics- Atomic & Molecular Properties & Theory