Structure and optical polarizabilities of small silicon clusters
Abstract
Possible structures of an Si10 cluster were examined using a tight binding model. Obtained stable geometries agree well with those from ab initio methods and classical potential methods. However, a new lowest energy geometry was found. It appears to be JahnTeller distorted, and therefore, it was not found with the other methods quoted above. The new structure also explains experimental photoelectron and chemical reactivity data. Electronic contributions of the linear and nonlinear optical properties of the Si10 cluster above and high symmetry clusters Si7 and Si13 were examined. The (hyper)polarizabilities alpha, beta and gamma were evaluated using one electron density matrix techniques in the form of sum over one electron states. The absorption cross section spectra were calculated in order to stimulate experimental work. Nonlinear polarizabilities were found to depend primarily on the symmetry of the cluster and proved to be high for low symmetry clusters. Possible experiments on the nonlinear properties are discussed.
 Publication:

Finnish Physical Society Conference Proceedings
 Pub Date:
 1991
 Bibcode:
 1991fnps.confX....R
 Keywords:

 Chemical Reactions;
 JahnTeller Effect;
 Mathematical Models;
 Optical Polarization;
 Optical Properties;
 Polarization Characteristics;
 Polyatomic Molecules;
 Silicon;
 Absorption Cross Sections;
 Electron Density (Concentration);
 Electron States;
 Matrix Methods;
 Nonlinear Optics;
 Nonlinear Systems;
 Photoelectrons;
 Symmetry;
 SolidState Physics