Accurate First Principles Prediction of ¹⁷O NMR Parameters in SiO₂:  Assignment of the Zeolite Ferrierite Spectrum

Abstract

17O NMR parameters, both the chemical shifts and the quadrupolar parameters, are calculated for SiO2 polymorphs using density functional theory with the generalized gradient-corrected PBE functional. The gauge including projector augmented wave (GIPAW) method (Pickard, C. J.; Mauri, F. Phys. Rev. B2001, 63, 245101) ensures the reproduction of all electron results while using computationally efficient pseudopotentials. The use of plane-waves permits fully converged calculations to be performed on structures containing 144 atoms in the unit cell, without the need to resort to the cluster approximation. The calculated NMR parameters of cristobalite, quartz, coesite, and faujasite are in excellent agreement with experimental data. This demonstrates that density functional theory is able to reproduce with high accuracy the 17O NMR parameters in SiO2 systems. This precision is used to assign the spectrum of the zeolite ferrierite. The data calculated for SiO2 are used to confirm that no simple correlation between the chemical shift and Cq NMR parameters and Si-O-Si angle exists, emphasizing the importance of predictive theories in this field.

Density functional theory investigation of3dtransition metal NMR shielding tensors in diamagnetic systems using the gauge-including projector augmented-wave method

“…The shielding parameters {σ iso , σ aniso , η σ } are deduced from the calculated eigenvalues using relations similar to (18), (19) and (20). One obtains σ iso = ⅓ (σ xx +σ yy +σ zz ) and η σ = η δ while σ aniso = -δ aniso according to the relation Within the framework of the pseudopotential approximation, the GIPAW method is able to converge towards all-electron magnetic response calculations.…”

“…Considering the rigid contribution of core electrons with respect to NMR parameters, [19] accuracy comparable to all electron calculations can be achieved. [5] Nevertheless the application to extended systems was, to date, limited to elements belonging to the first three rows of the periodic table, [20][21][22][23] due to the difficulties involved in efficient pseudopotential development.…”

Zero Thermal Expansion in ZrMgMo3O12: NMR Crystallography Reveals Origins of Thermoelastic Properties

“…For such systems, sophisticated correlation experiments are usually out of the question and the accessible observables in favorable situations only include the number of crystallographically distinct sites of a given element, the chemical shifts, and the electric field gradient (EFG) tensor parameters. Fortunately, the EFG tensor can be rapidly, and accurately, computed from projector augmented wave method density functional theory (PAW DFT) 52 calculations and has been used as a constraint for the refinement of the crystal structures of magnesium bromide, 53 sodium aluminoborate, 54 and sodium diphosphates. 55 ZrMgMo 3 O 12 is an ideal candidate for such a crystal structure refinement approach as the EFG tensors for all of the nuclei ( 17 O, 25 Mg, 91 Zr, and 95 Mo) can be determined experimentally via solid-state NMR.…”

High sensitivity of O17 NMR to p-d hybridization in transition metal perovskites: First principles calculations of large anisotropic chemical shielding

“…Linear response methods have long been used to calculateσ for isolated molecules and clusters. 7,8,9,10,11,12,13 In extended systems complications arise due to the use of periodic boundary conditions (PBC), 14,15,16 and implementations have been limited to planewave-based methods. Recently, an alternative to the linear response method has been proposed based on calculations of the orbital magnetization.…”