σ-bond expression for an analytic bond-order potential: Includingπand on-site terms in the fourth moment
| Autor: | Kurt Scheerschmidt, Volker Kuhlmann |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
Local density of states
Materials science Silicon chemistry.chemical_element Diamond Relative strength engineering.material Condensed Matter Physics Bond order Electronic Optical and Magnetic Materials chemistry Ab initio quantum chemistry methods Phase (matter) engineering Atomic physics Bond order potential |
| Zdroj: | Physical Review B. 76 |
| ISSN: | 1550-235X 1098-0121 |
| DOI: | 10.1103/physrevb.76.014306 |
| Popis: | An improved expression for bonds in sp-valent systems is derived for the analytical bond-order potential to four levels. The enhancement concerns the evaluation of the fourth moment of the local density of states with on-site and terms. The latter introduce a torsional stiffness to the -bond order, previously known only for the -bond order. The relative strength of the enhancement as compared to the pure terms depends on the ratio of the - and -bond integrals of the specific system. In the cubic diamond phase it is large for silicon 48% and rather small for carbon 5%. The potential parameters are given for silicon and the predicted properties are compared with ab initio calculations and experimental data. |
| Databáze: | OpenAIRE |
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