Ab initio prediction of Si-NMR chemical shifts.

The ability of several ab initio models to predict experimental Si-NMR chemical shift is examined. The shielding values of trimethylsilyl chloride (A), t-butyldimethylsilyl chloride (B) and allytrimethylsilane (C) are calculated by GIAO, CSGT and IGAIM methods, using HF/6-31G, B3LYP/6-31G, HF/6-311+G, B3LYP/6-311+G and MPW1PW91/6-311+G models respectively. The Si chemical shifts calculated by GIAO method using HF/6-311+G model are highly in agreement with those obtained experimentally. All of the models above reproduce the trends of chemical shifts in all cases studied, suggesting that the models are of practical value. [ABSTRACT FROM AUTHOR]