Comparison of the boys and Pipek-Mezey localizations in the local correlation approach and automatic virtual basis selection

Our implementation of Pipek–Mezey population localization is described. It is compared with other localization schemes and its use in the framework of the local correlation method is discussed. For such use, this localization is shown to be clearly superior to Boys in the case of physically well‐localized systems. Our current algorithm for selection of local virtual spaces is also described. © 1993 John Wiley & Sons, Inc.