中国物理B ›› 1993, Vol. 2 ›› Issue (6): 423-429.doi: 10.1088/1004-423X/2/6/003

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STRUCTURES OF Si AND Ge CLUSTERS UNDER MODIFIED STILLINGER-WEBER POTENTIAL

王坚, 资剑, 张开明, 谢希德   

  1. Department of Physics, Fudan University, Shanghai 200433, China
  • 收稿日期:1992-08-08 出版日期:1993-06-20 发布日期:1993-06-20

STRUCTURES OF Si AND Ge CLUSTERS UNDER MODIFIED STILLINGER-WEBER POTENTIAL

WANG JIAN (王坚), ZI JIAN (资剑), ZHANG KAI-MING (张开明), XIE XI-DE (谢希德)   

  1. Department of Physics, Fudan University, Shanghai 200433, China
  • Received:1992-08-08 Online:1993-06-20 Published:1993-06-20

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摘要： Structural behaviors of silicon and germanium clusters under the recently proposed modified Stillinger-Weber (SW) potential have been studied by molecular dynamics method along with the con-jugate-gradient optimization. Since the SW potentials have been derived from the properties of bulk materials, it gives relatively large discrepancy when the cluster number is small, e.g. n=3 and 4. When n>4, the ground-state structures under the modified SW potential are close to that from the first-principle calculation. The binding energies are also improved under the modified SW potential. These results may be attributed to the relative enhancement of the two-body term over the three-body term in the modified SW potential, which leads to structures with a preferential coordination number 4. Structural behaviors of germanium clusters are similar to those of silicon.

Abstract: Structural behaviors of silicon and germanium clusters under the recently proposed modified Stillinger-Weber (SW) potential have been studied by molecular dynamics method along with the con-jugate-gradient optimization. Since the SW potentials have been derived from the properties of bulk materials, it gives relatively large discrepancy when the cluster number is small, e.g. n=3 and 4. When n>4, the ground-state structures under the modified SW potential are close to that from the first-principle calculation. The binding energies are also improved under the modified SW potential. These results may be attributed to the relative enhancement of the two-body term over the three-body term in the modified SW potential, which leads to structures with a preferential coordination number 4. Structural behaviors of germanium clusters are similar to those of silicon.

中图分类号:  (Structure of clusters (e.g., metcars; not fragments of crystals; free or loosely aggregated or loosely attached to a substrate))

  • 61.46.Bc
71.15.Pd (Molecular dynamics calculations (Car-Parrinello) and other numerical simulations) 71.15.Nc (Total energy and cohesive energy calculations)