Departamento de Ciencias y Técnicas Fisicoquímicas, Facultad de Ciencias, Universidad Nacional de Educación a Distancia, Paseo de la Senda del Rey 9, 28040 Madrid, Spain.
J Chem Phys. 2018 Mar 14;148(10):102312. doi: 10.1063/1.5000007.
The problem of the equilibrium triplet structures in fluids with quantum behavior is discussed. Theoretical questions of interest to the real space structures are addressed by studying the three types of structures that can be determined via path integrals (instantaneous, centroid, and total thermalized-continuous linear response). The cases of liquid para-H and liquid neon on their crystallization lines are examined with path-integral Monte Carlo simulations, the focus being on the instantaneous and the centroid triplet functions (equilateral and isosceles configurations). To analyze the results further, two standard closures, Kirkwood superposition and Jackson-Feenberg convolution, are utilized. In addition, some pilot calculations with path integrals and closures of the instantaneous triplet structure factor of liquid para-H are also carried out for the equilateral components. Triplet structural regularities connected to the pair radial structures are identified, a remarkable usefulness of the closures employed is observed (e.g., triplet spatial functions for medium-long distances, triplet structure factors for medium k wave numbers), and physical insight into the role of pair correlations near quantum crystallization is gained.
本文讨论了具有量子行为的流体中平衡三重态结构的问题。通过研究可以通过路径积分（瞬时、质心和总热化连续线性响应）确定的三种结构，解决了对实空间结构感兴趣的理论问题。利用路径积分蒙特卡罗模拟研究了液 Para-H 和液氖在其结晶线上的情况，重点是瞬时和质心三重态函数（等边和等腰配置）。为了进一步分析结果，使用了两种标准闭包，Kirkwood 叠加和 Jackson-Feenberg 卷积。此外，还对液 Para-H 的瞬时三重态结构因子进行了一些带有路径积分和闭包的初步计算，用于等边分量。确定了与对径向结构相关的三重态结构规律，观察到所使用闭包的显著有用性（例如，中等长距离的三重态空间函数、中等 k 波数的三重态结构因子），并深入了解了量子结晶附近对关联的作用。
