Full-Scale Ab Initio Simulation of Magic-Angle-Spinning Dynamic Nuclear Polarization

• Published in: The journal of physical chemistry letters Vol. 11; no. 14; pp. 5655 - 5660
• Main Authors: Perras, Frédéric A, Raju, Muralikrishna, Carnahan, Scott L, Akbarian, Dooman, van Duin, Adri C. T, Rossini, Aaron J, Pruski, Marek
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 16-07-2020
• Subjects: Chemical calculations, Polarization; Computer Simulation; Diffusion; Hydrogen - chemistry; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Isotopes - chemistry; Models, Chemical; Molecular Dynamics Simulation; Molecular structure; Monte Carlo Method; Physical Insights into Chemistry, Catalysis, and Interfaces; Proton Magnetic Resonance Spectroscopy; Quantum mechanics; Silicon - chemistry
• ISSN: 1948-7185; 1948-7185
• DOI: 10.1021/acs.jpclett.0c00955

Theoretical models aimed at describing magic-angle-spinning (MAS) dynamic nuclear polarization (DNP) NMR have great potential in facilitating the in silico design of DNP polarizing agents and formulations. These models must typically face a trade-off between the accuracy of a strict quantum mechanical description and the need for using realistically large spin systems, for instance, using phenomenological models. Here, we show that the use of aggressive state-space restrictions and an optimization strategy allows full-scale ab initio MAS-DNP simulations of spin systems containing thousands of nuclei. Our simulations are shown to reproduce experimental DNP enhancements quantitatively, including their MAS rate dependence, for both frozen solutions and solid materials. They also reveal the importance of a previously unrecognized structural feature found in some polarizing agents that helps minimize the sensitivity losses imposed by the spin diffusion barrier.