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arXiv 2204.01804physics.chem-ph
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q-AQUA:多体CCSD(T)水势,包括四体相互作用,证明了水从团簇到液相的量子本质

q-AQUA: a many-body CCSD(T) water potential, including 4-body interactions, demonstrates the quantum nature of water from clusters to the liquid phase

Qi Yu, Chen Qu, Paul L. Houston, Riccardo Conte, Apurba Nandi, Joel M. Bowman

摘要:

许多模型势能面(PES)已被报道的水,但是,没有严格的“第一原理”。在这里,我们报告这样一个潜在的基础上,在CCSD(T)水平的理论的最终四体相互作用的多体表示。新的PES是基准的水六聚体的异构体的离解能,谐波频率,和无限制扩散蒙特卡罗(DMC)计算的零点能量的棱镜,书,笼异构体。20-mer的几种异构体的解离能与最近的基准能量吻合得很好。探索性DMC计算验证了新的PES的量子模拟的鲁棒性。新的PES的准确性和速度被证明为标准的凝聚相性质,即,径向分布函数和自扩散常数。量子效应被证明是这些可观的,也需要使理论与实验非常一致。

英文摘要:

Many model potential energy surfaces (PESs) have been reported for water; however, none are strictly from "first principles". Here we report such a potential, based on a many-body representation at the CCSD(T) level of theory up to the ultimate 4-body interaction. The new PES is benchmarked for the isomers of the water hexamer for dissociation energies, harmonic frequencies, and unrestricted diffusion Monte Carlo (DMC) calculations of the zero-point energies of the Prism, Book, and Cage isomers. Dissociation energies of several isomers of the 20-mer agree well with recent benchmark energies. Exploratory DMC calculations on this cluster verify the robustness of the new PES for quantum simulations. The accuracy and speed of the new PES are demonstrated for standard condensed phase properties, i.e., the radial distribution function and the self-diffusion constant. Quantum effects are shown to be substantial for these observables and also needed to bring theory into an excellent agreement with experiment.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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