“…Pyrex @ , or optical glasses and also for storage of nuclear waste. A considerable amount of results have been obtained about the structure of these glasses [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19], mainly via NMR analyses of 11 B, 17 O, 23 Na and 29 Si, Raman spectroscopy and neutron diffraction [18]. A comprehensive model was proposed almost 30 years ago in the present journal by Yun and Bray, Yun et al [1,2] and by Dell et al [3], based on experimental 11 O 3 ] (where [Á] mol%) are the most important composition-related structural parameters.…”