Hi relax. I read GUI 2011 paper and the 2007 review. It mentions the necessity to obtain experimental data at two different field strength. We are equipped with a 750 and 800 MHz Varian spectrometer, and I now wonder if this field separation is "enough". The 2008,a paper describes 500/600 MHz combination to solve the double minimum problem. But I wonder if this could be solved also for a 750/800 MHz data acquisition? Best Troels Emtekær Linnet