NMR

Statistical Learning of NMR tensors from 2D Isotropic/Anisotropic Correlation Nuclear Magnetic Resonance Spectra

Many linear inversion problems involving Fredholm integrals of the first kind are frequently encountered in the field of magnetic resonance. One important application is the direct inversion of a solid-state NMR spectrum containing multiple …

Correlating structural distributions in silica glass with two-dimensional $J$-resolved spectroscopy

A two-dimensional (2D) $J$-resolved magic-angle spinning nuclear magnetic resonance (NMR) spectrum of silica glass at $^{29}$Si natural abundance levels, 4.7%, was measured using the shifted-echo phase-incremented echo train acquisition (SE-PIETA) …

Correlating geminal $^2J_\text{Si–O–Si}$ couplings to structure in framework silicates

The dependence of a $^{29}$Si geminal J coupling across the inter-tetrahedral linkage on local structure was examined using first-principles DFT calculations. The two main influences on $^2J_\mathrm{Si–O–Si}$ were found to be a primary dependence on …

Nuances of multi-quantum excitation in solid state NMR of quadrupolar nuclei

In this article, a simple heuristic approach that is in agreement with the density operator formalism is presented for understanding the mechanism of multi-quantum (MQ) excitation in half-integral quadrupolar systems. Employing the population level …

Understanding multi-quantum NMR through secular approximation

With the development of technology and improved understanding of nuclear spin–spin interactions and their behavior in static/oscillating magnetic fields, NMR spectroscopy has emerged as a powerful tool for characterizing molecular structure in a wide …

Concept of effective Hamiltonians for transitions in multi-level systems

Employing the concept of effective Hamiltonians, an analytical theory is introduced to describe transitions in a multi-level system in nuclear magnetic resonance (NMR) spectroscopy. Specifically, the discussion is centered towards the treatment of …