Role of exchange in density-functional theory for weakly interacting systems: Quantum Monte Carlo analysis of electron density and interaction energy

作     者：Yosuke Kanai Jeffrey C. Grossman 

作者机构：Berkeley Nanosciences and Nanoengineering Institute University of California Berkeley California 94720 USA Department of Materials Science and Engineering Massachusetts Institute of Technology Massachusetts 02139 USA 

出 版 物：《Physical Review A》 (物理学评论A辑：原子、分子和光学物理学)

年 卷 期：2009年第80卷第3期

页      面：032504-032504页

核心收录：

学科分类：070207[理学-光学] 07[理学] 08[工学] 0803[工学-光学工程] 0702[理学-物理学] 

基　　金：University of California  BerKeley 

主　　题：Density functional theory 

摘      要：We analyze the density-functional theory (DFT) description of weak interactions by employing diffusion and reptation quantum Monte Carlo (QMC) calculations, for a set of benzene-molecule complexes. While the binding energies depend significantly on the exchange-correlation approximation employed for DFT calculations, QMC calculations show that the electron density is accurately described within DFT, including the quantitative features in the reduced density gradient. We elucidate how the enhancement of the exchange-energy density at a large reduced density gradient plays a critical role in obtaining accurate DFT description of weakly interacting systems.