Measurement of Ground State Correlation Effects on the Pair Correlation Function of Atoms and Molecules by X-Ray Scattering

Peter Lykos和Russ Bonham在理论和计算化学项目的支持下，在阿贡国家实验室的先进光源上对原子和分子的对相关函数进行实验测量。他们的合作还将包括从观察到的对相关函数中提取电子-电子排斥势能的理论处理。后一个量是电子相关的敏感度量，因此本研究将提供一组基准，用于测试新的量子化学电子相关处理和基集。所有量子化学计算的核心是基集和电子相关方法的双重选择。随着近十年来计算能力的显著提高，计算出的原子和分子的总能量已接近实验所得。为了进一步提高我们对量子化学中基集设计和近似相关技术的理解，需要更精确的基准。

Peter Lykos and Russ Bonham are supported by the Theoretical and Computational Chemistry Program to perform experimental meaurements of pair-correlation functions of atoms and molecules at the Advanced Light Source at Argonne National Laboratory. Their collaborative effort will also include a theoretical treatment to extract from the observed pair-correlation functions the electron-electron repulsive potential energies. This latter quantity is a sensitive measure of electron correlation, and thus this research will provide a set of benchmarks against which new quantum chemical electron correlation treatments and basis sets can be tested. At the core of all quantum chemistry computations are the twin choices of basis set and electron correlation method. With the remarkable increase in computational power in the last decade, calculated total energies of atoms and molecules approach those obtained experimentally. To further improve our understanding of basis set design and approximate correlation techniques in quantum chemistry, more precise benchmarks are necessary.