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arXiv · 2605.14611

A Flexible, Automated, and Basis-Set Insensitive Domain-Based Charge-Transfer Decomposition for Correlated Wavefunctions and its Application to Inter- and Intramolecular Cases

Lena Szczuczko·Julia Szczuczko·Marta Gałyńska·Katharina Boguslawski
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Abstract

We present a flexible, automated, and basis-set insensitive domain-based charge-transfer (CT) decomposition framework that can be combined with any CI-type excited-state wavefunction. Our approach is not based on excited-state densities and allows the excited-state character to be dissected into local and domain-based CT excitations and measures the individual contributions to each excited state. To guarantee a broad applicability, we introduce two domain-accumulation strategies to translate hole-particle substitutions to domain-domain excitations: a strict domain partitioning and a weighted approach suitable for small molecules and a large number of domains. The performance of both schemes is assessed for inter- and intramolecular CT excitations and various basis sets using EOM-CCSD and its simplified counterpart EOM-pCCD+S. Most importantly, the CT character is, to a large extent, basis-set independent, and both domain-accumulation schemes give consistent results. Overall, our framework provides a robust CT analysis and a domain resolution of the excitation character for a variety of computational setups and excited-state models.

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Lena Szczuczko, Julia Szczuczko, Marta Gałyńska, Katharina Boguslawski. 2026-05-14. A Flexible, Automated, and Basis-Set Insensitive Domain-Based Charge-Transfer Decomposition for Correlated Wavefunctions and its Application to Inter- and Intramolecular Cases. https://arxiv.org/abs/2605.14611

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