EAGER: Correlator product states for quantum chemistry and quantum Monte Carlo

康奈尔大学的Garnet K. Chan和Cyrus Umrigar获得了“理论、模型和计算方法”项目的EAGER奖，用于探索一类新的电子波函数。这样的波函数有可能创造一个新的量子化学框架，使研究具有全局包含电子相关的电子结构成为可能。新方法涉及被称为相关积态（CPS）的状态组，这些状态组与已建立的电子结构方法（如配置相互作用，耦合簇，双源等）中使用的波函数有根本不同。对模型系统的初步研究表明，CPS比其他波函数更准确、更有效地描述强相关量子问题。在这个探索性项目中，CPS方法被扩展到描述小分子和元素簇的解离。新的波函数作为扩散量子蒙特卡罗研究的起点是非常有用的。目前正在进行的步骤表明，CPS ansatz提供了理解整个电子相关性的框架，这些相关性是过渡金属化学、激发态、断键和复杂材料的核心。通过使用量子化学和量子蒙特卡罗方法探索影响化学家和材料科学家广泛受众的电子结构研究的变革性方法，实现了更广泛的影响。

Garnet K. Chan and Cyrus Umrigar of Cornell University are funded by an EAGER award from the Theory, Models and Computational Methods program to explore a novel class of electronic wave functions. Such wave functions have the potential of creating a new quantum chemistry framework enabling studies of electronic structure with global inclusion of electron correlation. The new approach involves groups of states referred as Correlator Product States (CPS) that are fundamentally different from the wave functions used in established electronic structure approaches such as configuration interaction, coupled cluster, geminal, among others. Initial studies on model systems show that CPS can describe strongly correlated quantum problems more accurately and more efficiently than other classes of wave functions. In this exploratory project the CPS approach is extended to describe dissociation of small molecules and elemental clusters. The new wave functions are very useful as the starting point in diffusion quantum Monte Carlo studies. Currently steps are underway to show that the CPS ansatz provides the framework for understanding an entire class of electronic correlations that are central to transition metal chemistry, excited states, bond-breaking, and complex materials. Broader impacts are achieved by the transformative approach to explore electronic structure studies that affect a broad audience of chemists and material scientists using quantum chemistry and quantum Monte Carlo methodologies.