Theoretical and Computational Studies of Quantum Dynamical Processes in Condensed Matter Systems

格雷戈里·沃斯得到了理论和 计算化学程序进行量子动力学的研究 凝聚相系统中的工艺。 他会利用 费曼路径中虚时间路径质心的性质 积分公式 时间位置相关函数 将使用质心分子动力学计算多体系统。 在 该方法类似经典的运动方程生成质心 这些轨迹是相关的，并与 相空间费曼路径积分形心密度。 所得 然后，相关函数可以通过傅立叶变换与 量子位置相关函数 将开发新算法 解决质心分子动力学方程，他们将 适用于许多凝聚相研究，包括：1）量子 液态水中的隧穿和模式量子化效应; 2）扩散 量子化水中水合电子的输运;以及3）量子 水和相关系统中过剩质子的动力学运动。 气相化学系统已经研究了许多年， 优秀的理论和计算技术已经发展到 模仿他们的行为。 最近的理论和计算 正在开发的方法使治疗更复杂的 凝聚相系统 目前的大多数理论模型都是 经典的性质，不能处理额外的并发症 由量子效应造成的。 沃斯的研究解决了这一额外的 的复杂程度，并提出了发展计算 允许处理凝相系统的方法 其包括各种量子自由度。

Gregory Voth is supported by a grant from the Theoretical and Computational Chemistry Program to perform studies of quantum dynamical processes in condensed phase systems. He will employ the dynamical properties of the imaginary time path centroid in the Feynman path integral formulation. The time position correlation function in many-body systems will be computed using centroid molecular dynamics. In this method classical-like equations of motion generate centroid trajectories which are correlated and statistically weighted with the phase space Feynman path integral centroid density. The resulting correlation function can then be related by Fourier transform to the quantum position correlation function. New algorithms will be developed to solve the centroid molecular dynamics equations, and they will be applied to a number of condensed phase studies including: 1) quantum tunneling and mode quantization effects in liquid water; 2) diffusive transport of the hydrated electron in quantized water; and 3) the quantum dynamical motion of an excess proton in water and related systems. Gas phase chemical systems have been studied for a number of years, and excellent theoretical and computational techniques have been developed to model their behavior. More recently theoretical and computational methods are being developed which make it possible to treat more complex condensed phase systems. Most of the current theoretical models are classical in nature, and cannot deal with the additional complications imposed by quantum effects. Voth's research addresses this additional degree of complexity, and proposes the development of computational approaches which will permit the treatment of condensed phase systems which include various quantum degrees of freedom.