caa a22 4500 605487693 CHVBK 20210128100452.0 cr unu---uuuuu 210128e20150301xx s 000 0 eng 10.1007/s00214-015-1638-2 doi (NATIONALLICENCE)springer-10.1007/s00214-015-1638-2 Barsberg Søren University of Copenhagen, Rolighedsvej 23, 1958, Frederiksberg C, Denmark aut Identification of the best DFT functionals for a reliable prediction of lignin vibrational properties [Elektronische Daten] [Søren Barsberg] Lignin is the most abundant aromatic plant polymer on earth. Useful information on its structure and interactions is gained by vibrational spectroscopy and relies on the quality of band assignments. B3LYP predictions were recently shown to support band assignments. Further progress calls for a comprehensive study of the quality of available theoretical methods in relation to the task of predicting lignin vibrational properties. The present study examined more than 50 functionals for prediction of IR vibrations of an appropriate lignin model. Based on a basis set incompleteness study, the pc-2 basis set was used. B98, X3LYP and B97-1 were the overall best-performing functionals, and "fingerprint” band positions were predicted by single-factor scaling of harmonic frequencies to an average error of ±3cm−1 by optimized scaling factors of 1.017, 1.021 and 1.016, respectively. Their performance using instead explicit anharmonic correction was slightly worse giving an error of ca. ±5cm−1. The X3LYP and B97-1 functionals offer also good description of hydrogen bonding. Error compensation from, e.g., insufficient treatment of solvation is likely to affect these results, and thus at this stage no single functional stands out. These results provide a needed basis for further theoretical developments in relation to vibrational assignments of Infrared and Raman spectra of lignin. Springer-Verlag Berlin Heidelberg, 2015 Lignin nationallicence Infrared nationallicence Raman nationallicence Density functional theory nationallicence Assignments nationallicence Theoretical Chemistry Accounts Springer Berlin Heidelberg 134/3(2015-03-01), 1-12 1432-881X 134:3<1 2015 134 214 https://doi.org/10.1007/s00214-015-1638-2 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00214-015-1638-2 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Barsberg Søren University of Copenhagen, Rolighedsvej 23, 1958, Frederiksberg C, Denmark aut NATIONALLICENCE 773 0- Theoretical Chemistry Accounts Springer Berlin Heidelberg 134/3(2015-03-01), 1-12 1432-881X 134:3<1 2015 134 214