biostudies-literatureWeidlich AMDeutsche Forschungsgemeinschafte70211https://www.ebi.ac.uk/biostudies/studies/S-EPMC12360141biostudies-literatureUnknown46(23)For existing and potential applications of acenes and acene derivatives, properties of their excited states play a central role. In describing these, the molecular orbital picture can reach its limits, and consideration within the quasi-particle picture can enable further insight. In this work, exciton size ( dexc$$ {d}_{exc} $$ ), hole and electron size ( σh$$ {\sigma}_h $$ and σe$$ {\sigma}_e $$ ) and correlation coefficient ( Reh$$ {R}_{eh} $$ ) of excited states of acenes and acene cations are investigated using TD-DFT at the TDA/CAM-B3LYP/6-311G* level, with a focus on their development with increasing acene length. Furthermore, employing a previously established approach, it is shown that the electronic structure of the ¹B_b and ²B_b states oJournal of computational chemistryMolecular Excitons and Plasmons in Acenes and Their Radical Cations.PMC12360141SFB 1249Weidlich AMDreuw AfalseMolecular Excitons and Plasmons in Acenes and Their Radical Cations.For existing and potential applications of acenes and acene derivatives, properties of their excited states play a central role. In describing these, the molecular orbital picture can reach its limits, and consideration within the quasi-particle picture can enable further insight. In this work, exciton size ( dexc$$ {d}_{exc} $$ ), hole and electron size ( σh$$ {\sigma}_h $$ and σe$$ {\sigma}_e $$ ) and correlation coefficient ( Reh$$ {R}_{eh} $$ ) of excited states of acenes and acene cations are investigated using TD-DFT at the TDA/CAM-B3LYP/6-311G* level, with a focus on their development with increasing acene length. Furthermore, employing a previously established approach, it is shown that the electronic structure of the ¹B_b and ²B_b states o2025-01-01T00:00:00Z2025 Sep2026-05-01T01:37:37.971Z2026-04-07T16:33:09.755ZS-EPMC123601414082400510.1002/jcc.70211