| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1561856 | Computational Materials Science | 2012 | 7 Pages |
The static electric polarizability and absorption spectrum of the coupled noble metal (Ag, Au, Cu) cluster-pair are investigated within density functional theory (DFT). The results show that the HOMO–LUMO gap gradually widens with increasing cluster distance D, and the static polarizability exhibits a maximal value as D is near the average bond length of cluster. In the absorption spectrum, the spectral strength is related to electric dipole moments which sensitively rely on D. With the increase of D the low-energy peaks (LEPs) obviously blue shift while the high-energy peaks (HEPs) keep their positions unmoved. The LEPs (HEPs) mostly comes from the transitions between near (far) the HOMO and LUMO energy levels. In these transitions, the low-energy excitations are dominantly contributed by d-electrons, indicating the fact that intense coupling effects can weaken the screen of d-electrons on sp-electrons. By means of the competition mechanism between charge transfer and electron cloud distortion, the spacing dependence behaviors of both electric and optical properties are explained self-consistently.
► The electric and optical properties of a cluster-pair rely on cluster interval D. ► The maximal polarizability is presented as D is near the bond length of cluster. ► The low-energy (high-energy) peaks blue shift (keep unmoved) with increasing D. ► Intercluster coupling can weaken the screen of d-electrons on sp-electrons. ► The electronic behaviors are discussed for explaining calculated results properly.
