Journal ArticleDOI
Refining Crystal Structures with Quadrupolar NMR and Dispersion-Corrected Density Functional Theory
Sean T. Holmes,Robert W. Schurko +1 more
TLDR
In this article, dispersion-corrected plane-wave density functional theory (DFT) is used to refine atomic coordinates in organic crystals determined initially through single-crystal X-ray diffraction (XRD) or neutron diffraction methods.Abstract:
Nuclear electric field gradient (EFG) tensors obtained from solid-state NMR spectroscopy are highly responsive to variations in structural features. The orientations and principal components of EFG tensors show great variation between different molecular structures; hence, extraction of EFG tensor parameters, either experimentally or computationally, provides a powerful means for structure determination and refinement. Here, dispersion-corrected plane-wave density functional theory (DFT) is used to refine atomic coordinates in organic crystals determined initially through single-crystal X-ray diffraction (XRD) or neutron diffraction methods. To accomplish this, an empirical parametrization of a two-body dispersion force field is illustrated, in which comparisons of experimental and calculated 14N, 17O, and 35Cl EFG tensor parameters are used to assess the quality of energy-minimized structures. The parametrization is based on a training set of 17 organic solids. The analysis is applied subsequently to the...read more
Citations
More filters
Journal ArticleDOI
NMR crystallography of molecular organics.
TL;DR: It is shown how "NMR crystallography" has been used in a spectrum of applications from resolving ambiguities in diffraction-derived structures to deriving complete structures in the absence of diffraction data.
Journal ArticleDOI
Higher Magnetic Fields, Finer MOF Structural Information: 17O Solid-State NMR at 35.2 T.
Vinicius Abilio Martins,Jun Xu,Xiaoling Wang,Kuizhi Chen,Ivan Hung,Zhehong Gan,Christel Gervais,Christian Bonhomme,Shijia Jiang,Anmin Zheng,Bryan E. G. Lucier,Yining Huang +11 more
TL;DR: This demonstration of the very high resolution of 17O SSNMR recorded at the highest magnetic field accessible to chemists to date illustrates how a broad variety of scientists can now study oxygen-containing materials and obtain previously inaccessible fine structural information.
Journal ArticleDOI
TensorView: A software tool for displaying NMR tensors.
TL;DR: A new computational tool, TensorView, for depicting NMR tensors on the molecular framework is described, which makes use of the graphical interface and built‐in molecular display functionality present within the Mathematica programming environment and is robust for displaying tensor properties from a broad range of commercial and user‐specific computational chemistry packages.
Journal ArticleDOI
Chemical Shift Tensors of Cimetidine Form A Modeled with Density Functional Theory Calculations: Implications for NMR Crystallography
Sean T. Holmes,Olivia G. Engl,Matthew N. Srnec,Jeffry D. Madura,Rosalynn Quiñones,James K. Harper,Robert W. Schurko,Robbie J. Iuliucci +7 more
TL;DR: Calculations of 13C and 15N magnetic shielding tensors using hybrid functionals show better agreement with experimental values in comparison to those using GGA functionals, independent of the method of structural refinement; the shielding of carbon atoms bonded to nitrogen are especially improved using hybrid DFT methods.
Journal ArticleDOI
Mechanochemical syntheses and 35Cl solid-state NMR characterization of fluoxetine HCl cocrystals
TL;DR: In this paper, a combination of powder X-ray diffraction (PXRD) and solid-state NMR (SSNMR) spectroscopy was used to synthesize high-purity fluoxetine HCl cocrystals using neat grinding or liquid assisted grinding.
References
More filters
Journal ArticleDOI
A consistent and accurate ab initio parametrization of density functional dispersion correction (DFT-D) for the 94 elements H-Pu
TL;DR: The revised DFT-D method is proposed as a general tool for the computation of the dispersion energy in molecules and solids of any kind with DFT and related (low-cost) electronic structure methods for large systems.
Journal ArticleDOI
Semiempirical GGA-type density functional constructed with a long-range dispersion correction.
TL;DR: A new density functional of the generalized gradient approximation (GGA) type for general chemistry applications termed B97‐D is proposed, based on Becke's power‐series ansatz from 1997, and is explicitly parameterized by including damped atom‐pairwise dispersion corrections of the form C6 · R−6.
Journal ArticleDOI
First principles methods using CASTEP
Stewart J. Clark,Matthew D. Segall,Chris J. Pickard,P. J. Hasnip,Matt Probert,Keith Refson,Mike C. Payne +6 more
TL;DR: The CASTEP program as mentioned in this paper is a computer program for first principles electro-Nic structure calculations, and some of its features and capabilities are described and near-future development plans outlined.
Journal ArticleDOI
Long-range corrected hybrid density functionals with damped atom–atom dispersion corrections
Jeng-Da Chai,Martin Head-Gordon +1 more
TL;DR: The re-optimization of a recently proposed long-range corrected hybrid density functional, omegaB97X-D, to include empirical atom-atom dispersion corrections yields satisfactory accuracy for thermochemistry, kinetics, and non-covalent interactions.
Journal ArticleDOI
Improved adsorption energetics within density-functional theory using revised Perdew-Burke-Ernzerhof functionals
TL;DR: In this paper, a simple formulation of a generalized gradient approximation for the exchange and correlation energy of electrons has been proposed by Perdew, Burke, and Ernzerhof (PBE), which improves the chemisorption energy of atoms and molecules on transition-metal surfaces.
Related Papers (5)
All-electron magnetic response with pseudopotentials: NMR chemical shifts
Chris J. Pickard,Francesco Mauri +1 more