AUTHOR=Böckmann Marcus, Doltsinis Nikos L. TITLE=Can Excited Electronic States of Macromolecules with Extended Pi-Systems be Reliably Predicted? A Case Study on P3HT JOURNAL=Frontiers in Materials VOLUME=2 YEAR=2015 URL=https://www.frontiersin.org/articles/10.3389/fmats.2015.00025 DOI=10.3389/fmats.2015.00025 ISSN=2296-8016