Yıldırım, Erdem KamilDupree, R.2020-06-252020-06-252005closedAccess0217-9849https://doi.org/10.1142/S0217984905009092https://hdl.handle.net/20.500.12587/3408dupree, ray/0000-0002-3334-0429The relation between O-17 quadrupolax parameters and the local structure in silicates is of considerable interest if these parameters are to be used as a local probe. Although there are a number of investigations and some theoretical work on Si-O-Si bonds, there seems to be very little experimental data on Si-O-Al bonds. We have therefore investigated a number of sodalites with a general formula of M-8[AlSiO4]Cl-2 where M is an alkali cation. They have only one oxygen site and a Si:Al ratio of one. By varying the alkali we were able to change the Si-O-Al bond angle about five degrees steps from 125 to 152 degrees. The value of the electric field gradient (EFG), C-Q of O-17, followed a roughly similar angular dependence to that found for Si-O-Si bonds with C-Q180 = 4.2 MHz. The asymmetry parameter of O-17 also behaved in a similar fashion to that found for Si-O-Si bonds although it increased more rapidly at small angles.eninfo:eu-repo/semantics/closedAccessO-17NMRquadrupole coupling constantasymmetry parameterArticle19241213122110.1142/S02179849050090922-s2.0-27744485601Q2WOS:000233699600003Q3