Dimitrov V.Komatsu T.2024-07-162024-07-162024-07-162024-07-162013-12-171314-74711314-7978SCOPUS_ID:84890174832https://rlib.uctm.edu/handle/123456789/1026The current status of the development of the optical basicity concept and Sun's approach on single bond strength to Bi2O3-B2O3, ZnO-Bi2O3-B2O3 and R2O-B2O3-SiO2 (R = Li, Na and K) glasses has been discussed. In all glass systems the optical basicity increases with decreasing average single bond strength. More acidic glasses possess large BM-O (480-320kJ/mol) which means participation of an average oxide ion in more covalent M-BO (bridging oxygen) bonds such as B-O-B and Si-O-Si. The smallest values of BM-O about 300-250 kJ/mol have been obtained for bismithate glasses. It has been assumed that these values support the formation of Bi-O-B, Bi-O-Bi, Zn-O-B and Zn-O-Bi bonds with increased ionicity.enArticle