Crystallographic and Dynamic Aspects of Solid-State NMR Calibration Compounds: Towards ab Initio NMR Crystallography.
The excellent results of dispersion-corrected density functional theory (DFT-D) calculations for static systems have been well established over the past decade. The introduction of dynamics into DFT-D calculations is a target, especially for the field of molecular NMR crystallography. Four (13) C ss-NMR calibration compounds are investigated by single-crystal X-ray diffraction, molecular dynamics and DFT-D calculations. The crystal structure of 3-methylglutaric acid is reported. The rotator phases of adamantane and hexamethylbenzene at room temperature are successfully reproduced in the molecular dynamics simulations. The calculated (13) C chemical shifts of these compounds are in excellent agreement with experiment, with a root-mean-square deviation of 2.0 ppm. It is confirmed that a combination of classical molecular dynamics and DFT-D chemical shift calculation improves the accuracy of calculated chemical shifts.
Department of Pharmacy, University of Copenhagen, Universitetsparken 2, DK-2100, Copenhagen, Denmark.
Xiaozhou
http://orcid.org/0000-0003-3882-7073
X
Li
Institute for Inorganic and Analytical Chemistry, Goethe University, Max-von-Laue-Strasse 7, D-60438, Frankfurt am Main, Germany.
Lukas
L
Tapmeyer
Institute for Inorganic and Analytical Chemistry, Goethe University, Max-von-Laue-Strasse 7, D-60438, Frankfurt am Main, Germany.
Michael
M
Bolte
Department of Pharmacy, University of Copenhagen, Universitetsparken 2, DK-2100, Copenhagen, Denmark. jaccovandestreek@yahoo.co.uk.
Jacco
http://orcid.org/0000-0002-3026-4213
J
van de Streek
NMR crystallography; X-ray diffraction; density functional calculations; molecular dynamics; solid-state NMR spectroscopy