The combination of spectroscopy analysis (Raman and IR) and MD simulation was applied to explore the structure characters of Bayer liquor. In this work, MD simulation had been used to probe the nature of sodium metal-aluminate ion pairing and its role in the stabilization of clusters. It was found that the maximum concentration of Al(OH)(4)(-) occurs in low caustic solutions, but in high caustic solution, the appearance of Al(OH)(3)(-) was found. Results of molecular dynamic simulation indicated that the formation of clustering of 6 aluminates in solution, and the clusters stabilized by sodium ions made a contribution to the formation of polyaluminate. (c) 2006 Elsevier B.V. All rights reserved.