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

南卡罗来纳州大学的Sophya Garashchuk获得了化学系理论、模型和计算方法项目的CAREER奖，以开发理论和计算方法，帮助回答这个问题，在研究化学过程时，什么时候考虑原子核的量子性质很重要？ Garashchuk博士和她的研究小组开发了可扩展到大型分子系统的近似量子轨道方法。这种方法是基于代表波函数的量子轨迹的合奏动力学。用于玻尔兹曼演化和本征态计算的虚时间量子轨道框架的发展使得能够直接计算热速率常数。主要的量子，固有的非本地，影响被纳入轨道动力学通过“平均场”型近似的量子力，这可以被关闭，以评估其在化学过程中的重要性。在大系统中的反应性的理论研究有助于在化学，物理，生物和材料科学的分子系统的基本理解。 Garashchuk博士还参与了许多推广计划，这些计划扩大了科学过程中代表性不足的群体的参与，吸引更多的年轻人从事研究型职业，并在地理上代表性不足的南卡罗来纳州的研究（符合EPSCoR条件）中带来更多的科学知名度和欣赏。 该项目开发的计算机代码可广泛提供给研究界，该项目由网络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.