The Na4(+3) Clusters in Sodium Sodalite
Abstract
We have measured and calculated the absorption spectrum of the Na4(3+) clusters in Na3(AlSiO4)3 sodalite prepared by high vacuum deposition of sodium atoms. The samples with a Na4(3+):Na3(3+) cluster ratio up to 1:10 show a single absorption feature with lambda max = 628 run (1.99 eV). The absorption originates from the individual sodalite cages containing Na4(3+) cluster. For the Na4(3+):Na3(3+) cluster ratio larger than 1:10, when some of the Na4(3+) clusters are likely to interact, the changes in absorption spectra indicate the onset of metal-insulator transition. Time dependent quantum mechanical calculations of the photon absorption cross section of Na4(3+) clusters in sodalite at infinite dilution were carried out. The dependence of the calculated spectra on sodalite framework charges and cluster geometry was used to determine which of the proposed charge distribution models are consistent with the absorption spectra. The best agreement between measurements and calculations is obtained for Na = +1, Si = +1.9, Al = +0.9, O = -0.95.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 15, 1992
- Accession Number
- ADA251602
Entities
People
- Galen D. Stucky
- H. Metiu
- K. Haug
- V. I. Srdanov
Organizations
- University of California, Santa Barbara