Optical and bonding characters of Hg type clusters

Abstract

The configuration, bonding, molecule orbitals and the wavelength of absorption spectra of HgX (X = O, Te, Se, and S) molecules and their doping clusters have been systematically investigated at B3LYP level with LanL2DZ basis set. The calculated results showed that Hg₂O₂ had different bonding, orbitals and spectra than other HgO clusters due to the presence of an O–O bond. From analysis of the calculated wavelengths of absorption spectra, we have found that Hg₄O₄ (a; hexahedron structure) and Hg₄O₄ (b; planar octagon) had completely different absorption wavelengths. As for doping, vacancy doping changed the HOMO and the LUMO, and the spectra of clusters. In contrast, substitution doping did not influence the orbital compositions of the structures. Obviously, vacancy doping was more difficult than substitution doping. Finally, through comparison of orbitals, spectra and bonding of HgO, HgS, HgSe and HgTe molecules, we have discovered that the other clusters had completely different orbital compositions, spectra, and bonding from of HgO clusters.