ISSN:
0020-7608
Keywords:
Polyethylene
;
energy bands
;
dispersion relation
;
Hamiltonian matrix eigenfunctions
;
non-one-dimensionality
;
Chemistry
;
Theoretical, Physical and Computational Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The alternative way of solving secular problems for the Hamiltonian matrices of regular quasi-one-dimensional systems developed previously [V. Gineityte, Int. J. Quant. Chem. 60(3), 717 (1996)] has been applied to polyethylene. An implicit form of the dispersion relation has been obtained in terms of three local-structure-determined energy-dependent functions δ(ε), τ(ε), and η(ε), describing the effective interactions inside a separate CH2 group and those between first- and second-neighboring CH2 groups, respectively. The actual shapes of dispersion curves proved to be determined by relative mean values of the functions τ(ε) and η(ε) within the ε region under interest. The unusual minimum within the low-energy branch of dispersion curves situated at a low-symmetry point of the first Brillouin zone (k≈0.6π/a) has been established to appear owing to considerable values of effective interactions between the second-neighboring CH2 groups within the respective energy interval. Just the latter type of interactions has been concluded to be responsible also for non-one-dimensionality of the polyethylene chain. The Hamiltonian matrix eigenfunctions of this chain have been expressed as the Bloch sums of eigenvalue-dependent local-structure-determined basis orbitals. © 1997 John Wiley & Sons, Inc. Int J Quant Chem 64: 481-494, 1997
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
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