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.

中文翻译：

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魔角旋转动态核极化的全比例从头算模拟。

旨在描述魔术角旋转（MAS）动态核极化（DNP）NMR的理论模型在促进DNP极化剂和配方的计算机设计方面具有巨大潜力。这些模型通常必须在严格的量子力学描述的准确性与使用实际大型自旋系统（例如，使用现象学模型）的需求之间进行权衡。在这里，我们证明了使用激进的状态空间限制和优化策略可以对包含数千个原子核的自旋系统进行从头开始的MAS-DNP模拟。我们的仿真显示可以定量再现实验性DNP增强，包括其对冷冻溶液和固体材料的MAS速率依赖性。