Elongation-CIS method: Describing excited states of large molecular systems in regionally localized molecular orbital basis

摘要

The elongation methodology is extended towards description of excited states through the ab initio CIS expansions in regionally localized molecular orbital basis. The formalism and implementation of the elongation-CIS method are presented. The expected accuracy of the method in comparison to the conventional CIS approach is illustrated by the results of calculations for model systems.