Chemical Physics Letters, Vol.509, No.4-6, 186-191, 2011
EASY-GOING DUMBO on-spectrometer optimisation of phase modulated homonuclear decoupling sequences in solid-state NMR
A one-step many-parameter optimisation scheme for phase modulated proton homonuclear decoupling sequences in solid-state NMR is presented. Phase modulations, parameterised by DUMBO Fourier coefficients, were optimised using a Covariance Matrix Adaptation Evolution Strategies algorithm. Our method, denoted EASY-GOING DUMBO, starts with featureless spectra and optimises proton-proton decoupling, during either proton or carbon signal detection. Optimisations at moderate sample magic angle spinning (MAS) frequencies and medium radio-frequency (rf) field strengths resulted in solutions closely resembling (e) DUMBO. Application of EASY-GOING DUMBO for optimisation at very high 680 kHz rf field strength, 12.5 kHz MAS on a 400 MHz NMR spectrometer resulted in a new solution, with competitively resolved proton spectra. (C) 2011 Elsevier B.V. All rights reserved.