Water continues to be the focus of a considerable number of experimental and theoretical investigations because of the important role it plays in many phenomena in fundamental and applied science, as well as its biological and technological importance. The ability of water to create a three-dimensional network of hydrogen bonds makes this molecule uniquely versatile. Atoms in water display characteristic mean kinetic energies well above the thermodynamic temperature of the system, as opposed to the celebrated case of a perfect gas of non-interacting particles. Nuclear quantum effects have a profound influence on the structure and dynamics of hydrogen-bonded systems, such as water. These effects are reflected in the underlying nuclear momentum distributions, experimentally accessible using electron-volt neutron spectroscopy at pulsed spallation neutron sources, with a technique known as deep inelastic neutron scattering. In this topical review, the technique is discussed along with the conceptual framework and several case studies that bring to the fore the role of nuclear quantum effects in describing water. These state-of-the-art measurements are also benchmarked against theoretical predictions using path-integral molecular dynamics. We close by discussing and highlighting current challenges and future opportunities in this thriving area of condensed-matter research.

中文翻译：

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凝聚态核量子效应的实验研究：以水为例

由于水在基础科学和应用科学中的许多现象中起着重要的作用，以及其生物学和技术重要性，因此水仍然继续是许多实验和理论研究的重点。水形成氢键三维网络的能力使该分子具有独特的用途。水中的原子显示特征的动能远高于系统的热力学温度，这与非相互作用粒子的理想气体的理想情况相反。核量子效应对氢键系统（例如水）的结构和动力学产生深远影响。这些影响反映在潜在的核动量分布中，使用电子伏特中子能谱在脉冲散裂中子源上进行实验性访问，并使用一种称为深层非弹性中子散射的技术。在本专题综述中，将讨论该技术以及概念框架和一些案例研究，这些研究突显了核量子效应在描述水方面的作用。这些最新的测量结果还使用路径积分分子动力学与理论预测进行了比较。最后，我们讨论并重点介绍了在凝聚态研究这一蓬勃发展的领域中当前的挑战和未来的机遇。讨论了该技术以及概念框架和一些案例研究，这些研究突显了核量子效应在描述水方面的作用。这些最新的测量结果还使用路径积分分子动力学与理论预测进行了比较。最后，我们通过讨论和重点介绍在这个凝聚态研究蓬勃发展的领域中当前的挑战和未来的机遇。讨论了该技术以及概念框架和一些案例研究，这些研究突显了核量子效应在描述水方面的作用。这些最新的测量结果还使用路径积分分子动力学与理论预测进行了比较。最后，我们讨论并重点介绍了在凝聚态研究这一蓬勃发展的领域中当前的挑战和未来的机遇。