CAREER: Approximate description of nuclear quantum effects applicable to large systems

南卡罗来纳大学的Sophya Garashchuk得到了化学系理论、模型和计算方法项目的职业奖的支持，该项目旨在开发理论和计算方法，帮助回答这样一个问题，即在研究化学过程时，何时考虑原子核的量子性质是重要的？加拉什丘克博士和她的研究小组开发了可扩展到大分子系统的近似量子轨迹方法。这种方法是基于代表一个波函数的量子轨迹系综的动力学。用于玻尔兹曼演化和本征态计算的虚时间量子轨迹框架的发展使热速率常数的直接计算成为可能。主要的非局域量子效应通过量子力的平均场类型的近似被结合到轨道动力学中，量子力可以被关闭以评估其在化学过程中的重要性。对大系统中反应性的理论研究有助于在化学、物理、生物学和材料科学中对分子系统的基本理解。加拉什丘克博士还参与了许多推广计划，这些计划扩大了代表不足的群体在科学过程中的参与，吸引更多的年轻人从事以研究为导向的职业，并在研究人数较少的南卡罗来纳州(符合EPSCoR资格)带来更多的科学知名度和鉴赏力。在这个项目中开发的计算机代码被广泛地提供给研究界。该项目由数码基础设施办公室共同资助。

Sophya Garashchuk of the University of South Carolina is supported by a CAREER award from the Theory, Models and Computational Methods program in the Chemistry division to develop theoretical and computational methods that help to answer the question, when is it important to take the quantum nature of the nuclei into account when studying chemical processes? Dr. Garashchuk and her research group develop approximate quantum trajectory methods that are scalable to large molecular systems. This methodology is based on the dynamics of an ensemble of quantum trajectories representing a wavefunction. The development of the quantum trajectory framework in imaginary time used for the Boltzmann evolution and eigenstate calculation enable the direct calculation of thermal rate constants. The dominant quantum, inherently non-local, effects are incorporated into trajectory dynamics through a "mean-field"-type approximation to the quantum force, which can be turned off to assess its importance in a chemical process.Theoretical studies of reactivity in large systems contribute to the fundamental understanding of molecular systems in chemistry, physics, and biology and material science. Dr. Garashchuk also engages in many outreach programs that broaden participation of underrepresented groups in the scientific process, attract more young people to research-oriented careers and bring more visibility and appreciation of science in a geographically underrepresented in research (EPSCoR eligible) state of South Carolina. The computer code developed in this project is made widely available to the research community.The project is co-funded by the Office of Cyberinfrastructure.