title: Efficient Modeling of NMR Parameters in Carbon Nanosystems.
abstract: Rapid growth of nanoscience and nanotechnology requires new and more powerful modeling tools. Efficient theoretical modeling of large molecular systems at the ab initio and Density Functional Theory (DFT) levels of theory depends critically on the size and completeness of the basis set used. The recently designed variants of STO-3G basis set (STO-3Gel, STO-3Gmag), modified to correctly predict electronic and magnetic properties were tested on simple models of pristine and functionalized carbon nanotube (CNT) systems and fullerenes using the B3LYP and VSXC density functionals. Predicted geometries, vibrational properties, and HOMO/LUMO gaps of the model systems, calculated with typical 6-31G* and modified STO-3G basis sets, were comparable. The (13)C nuclear isotropic shieldings, calculated with STO-3Gmag and Jensen's polarization consistent pcS-2 basis sets, were also identical. The STO-3Gmag basis sets, being half the size of the latter one, are promising alternative for studying (13)C nuclear magnetic shieldings in larger size CNTs and fullerenes.
authors.affiliation: University of Opole , Faculty of Chemistry, 48, Oleska Street, 45-052 Opole, Poland.
authors.forename: Teobald
authors.initials: T
authors.lastname: Kupka
authors.affiliation: University of Opole , Faculty of Chemistry, 48, Oleska Street, 45-052 Opole, Poland.
authors.forename: Michał
authors.initials: M
authors.lastname: Stachów
authors.affiliation: Division of Statistics, Department of Instrumental Analysis, Medical University of Silesia , 30 Ostrogórska Street, 41-200 Sosnowiec, Poland.
authors.forename: Elżbieta
authors.initials: E
authors.lastname: Chełmecka
authors.affiliation: A. Chełkowski Institute of Physics, University of Silesia , 4 Uniwersytecka Street, 40-007 Katowice, Poland.
authors.forename: Karol
authors.initials: K
authors.lastname: Pasterny
authors.affiliation: Institute of Theoretical Physics and Astrophysics, University of Gdańsk , 57 Wita Stwosza Street, 80-952 Gdańsk, Poland.|Institute of Physics, Polish Academy of Sciences , 32/46, al. Lotników, 02-668 Warsaw, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Stobińska
authors.affiliation: Institute of Physical Chemistry, Polish Academy of Sciences , 44/52 Kasprzaka Street, 01-224 Warsaw, Poland.
authors.forename: Leszek
authors.initials: L
authors.lastname: Stobiński
authors.affiliation: Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences , Flemingovo Nam. 2., 166 10 Prague, Czech Republic.
authors.forename: Jakub
authors.initials: J
authors.lastname: Kaminský