Genetic algorithms and solid state NMR pulse sequences

Rapid acquisition of wideline MAS solid-state NMR spectra with fast MAS, proton detection, and dipolar HMQC pulse sequences.

The solid-state NMR spectra of many NMR active elements are often extremely broad due to the presence of chemical shift anisotropy (CSA) and/or the quadrupolar interaction (for nuclei with spin I > 1/2). These NMR interactions often give rise to wideline solid-state NMR spectra which can span hundreds of kHz or several MHz. Here we demonstrate that by using fast MAS, proton detection and dipola...

Broadband population inversion in solid state NMR

We present theory, simulations and experimental demonstrations of composite 1T pulses for population inversion in coupled spin systems such as occur in solid state NMR. The composite 1T pulses are phase-shifted rf pulse sequences designed to invert spins over a larger range of dipole or quadrupole couplings than a conventional1T pulse, for a given rfpower. We discuss a previously proposed theor...

Efficient theory of dipolar recoupling in solid-state nuclear magnetic resonance of rotating solids using Floquet-Magnus expansion: application on BABA and C7 radiofrequency pulse sequences.

This article describes the use of an alternative expansion scheme called Floquet-Magnus expansion (FME) to study the dynamics of spin system in solid-state NMR. The main tool used to describe the effect of time-dependent interactions in NMR is the average Hamiltonian theory (AHT). However, some NMR experiments, such as sample rotation and pulse crafting, seem to be more conveniently described u...

Symmetry-Based Pulse Sequences in Magic-Angle Spinning Solid-State NMR

Spectral editing in solid-state NMR using scalar multiple quantum filters.

In this paper we describe the use of heteronuclear scalar couplings in solid-state NMR in order to generate multiple-quantum filtering (MQF) pulse sequences. These sequences can be used to edit CP/MAS spectra according to carbon multiplicity. Analytic expressions for the intensity of the MQF signals are obtained using the standard product operator formalism. Experiments that demonstrate the tec...