Title:	DFT Calculations of NMR Parameters and Structure Refinements of Glasses and Pharmaceutical Cocrystals
DNr:	NAISS 2026/3-343
Project Type:	NAISS Medium
Principal Investigator:	Mattias Edén <mattias.eden@su.se>
Affiliation:	Stockholms universitet
Duration:	2026-05-01 – 2027-05-01
Classification:	10402 10407 10403
Homepage:	http://www.su.se/profiles/eden-1.187322
Keywords:

Abstract

Computational modeling is a central component in two projects that share the common aim of an improved structural understanding but for distinctly different systems, ranging from refined structures of pharmaceutical salts and cocrystals to the amorphous structures of inorganic borosilicate and aluminosilicate glasses. 1.The KAW-funded project “Access to potent medical drugs through polymorph-specific crystallization enabled by ionic liquids” aims at steering the crystallization of polymorphic pharmaceutical compounds for obtaining a specifically targeted form. Here we utilize a very recently developed solid-state NMR crystallography method, which enables estimates of entire sets of 13C-1H and 1H-1H interatomic distances from polycrystalline powders. In conjunction with structural refinements by plane-wave DFT calculations along with computations of 1H and 13C chemical shifts by the gauge including projector augmented wave (GIPAW) method for assisting NMR-peak assignments, we will refine the structures of various cocrystals of pharmaceuticals. These computations will be performed along the lines of our recent publication on the disordered beta-caffeine form and its cocrystals with several diacids [Majhi et al., Phys. Chem. Chem. Phys. (2024)], as well as recently completed computations on paracetamol-based cocrystals. 2.Similar DFT/GIPAW calculations will also be utilized for predicting NMR parameters from glass models obtained by atomistic MD simulations within the project "Harnessing Exotic Structural Motifs in Borosilicate Glasses for Improved Structural Models", funded by the Swedish Research Council. Here we explore minor structural motifs, which have hitherto been considered “forbidden” in traditional glass theories/models, but which are consistently predicted by MD-generated glass models. Yet we recently proved the existence of some of these local glass motifs by advanced 2D NMR experiments [Yu, Stevensson, Edén, J. Phys. Chem. Lett. (2018)]. The computational work has thus far mainly involved atomistic molecular dynamics simulations, along with the prediction of 11B and 17O NMR parameters for assisting NMR spectral analyses. While those calculations for borosilicate glasses will proceed within the continuation project, the research will be expanded to encompass 17O NMR parameters for similar exotic motifs in aluminosilicate glasses [Stevensson, Edén, Acta Mater. (2025)].