CAREER: Accurate, Reliable, and Routine First-Principles Prediction of the Structure and Stability of Molecular Crystal Polymorphs

Robert A.小迪斯塔西奥康奈尔大学化学系的化学理论、模型和计算方法项目获得了一个奖项的支持，该奖项旨在开发能够准确可靠地预测分子晶体结构和稳定性的方法。分子晶体是无处不在的多功能材料，用于替代能源和环境科学，制药和医学以及技术和工业。对这些应用至关重要的是，分子晶体通常具有许多可接近的多晶型物，即稳定性几乎相同但显示出截然不同的物理和化学性质的替代结构。当用于改善器件性能或在替代能源应用中实现新功能时，这些独特的特性可能非常有益。多晶型物的存在也可能具有破坏性和潜在的灾难性影响，例如，当药剂意外地转化成未知（和无活性）多晶型物，从而减少抗病（和潜在地挽救生命）形式的量时。Distasio和他的研究小组正在开发准确可靠的方法，这些方法使用计算机模拟来预测基于量子和统计力学定律的分子晶体多晶型物的结构和稳定性。在此过程中，Distasio正在开发一个计算框架，以解决在新型能源解决方案和药剂中使用分子晶体多晶型物的新机会。 Distasio研究小组还在开发一个交互式分子动力学（MD）软件包，（K-12，本科生和研究生）将化学中遇到的抽象数学概念可视化，并建立物理和化学的直觉，关于观察到的性质和物质的微观结构之间的复杂相互作用。通过开发和利用国家的，结合了联合收割机量子和统计力学、数值分析和高性能计算的技术方法，Distasio和他的研究小组正在创建一个理论和算法框架，该框架利用稀疏性来实现生物学、化学、物理学和材料科学。这个框架同时解释了电子（包括复杂的交换相关效应）和原子核的量子力学性质，以及现实的实验条件（即，有限的温度和压力），因此能够根据第一原理对所有化学上（和动力学上）相关的分子晶体多晶型物的结构和稳定性进行准确、可靠和常规的预测。这些研究工作为增强对复杂多晶型能量景观的基本理解和基于预测性第一原理的晶体结构预测的常规使用铺平了道路，这两个奖项对于获得分子晶体的巨大和未开发的潜力都是至关重要的。该奖项反映了NSF的法定使命，并通过利用基金会的智力价值和更广泛的影响进行评估，被认为值得支持审查标准。

Professor Robert A. DiStasio Jr. of Cornell University is supported by an award from the Chemical Theory, Models and Computational Methods program in the Division of Chemistry to develop methods which enable accurate and reliable predictions of the structure and stability of molecular crystals. Molecular crystals are ubiquitous and versatile materials that are used in alternative energy and the environmental sciences, pharmaceuticals and medicine, as well as technology and industry. Of crucial importance to these applications is the fact that molecular crystals often have many accessible polymorphs—alternative structures that are nearly identical in stability yet display drastically different physical and chemical properties. When used to improve device performance or enable novel functions in alternative energy applications, these distinct properties can be very beneficial. The existence of polymorphs can also have devastating and potentially catastrophic effects, e.g., when a pharmaceutical agent unexpectedly converts into an unknown (and inactive) polymorph, and thereby reduces the amount of the disease-fighting (and potentially life-saving) form. DiStasio and his research group are developing accurate and reliable methods which use computer simulations to predict the structures and stabilities of molecular crystal polymorphs based on the laws of quantum and statistical mechanics. In doing so, DiStasio is developing a computational framework that addresses new opportunities to use molecular crystal polymorphs in novel energy solutions and pharmaceutical agents. The DiStasio research group is also developing an interactive molecular dynamics (MD) package which allows students at all levels (K-12, undergraduate, and graduate) to visualize the abstract mathematical concepts encountered in chemistry, and to build physical and chemical intuition regarding the complex interplay between observed properties and the microscopic structure of matter.By developing and utilizing state-of-the-art methods that combine quantum and statistical mechanics, numerical analysis, and high-performance computing, DiStasio and his research group are creating a theoretical and algorithmic framework which exploits sparsity to enable highly accurate ab initio molecular dynamics (AIMD) simulations of complex and large-scale condensed-phase systems of interest throughout biology, chemistry, physics, and materials science. This framework simultaneously accounts for the quantum mechanical nature of the electrons (including sophisticated exchange-correlation effects) and the nuclei, as well as realistic experimental conditions (i.e., finite temperatures and pressures), and therefore enables accurate, reliable, and routine predictions of the structures and stabilities of all thermodynamically (and kinetically) relevant molecular crystal polymorphs from first principles. These research efforts pave the way towards an enhanced fundamental understanding of complex polymorphic energy landscapes and the routine use of predictive first-principles based crystal structure prediction, both of which are crucial to accessing the vast and largely unexplored potential of molecular crystals.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.