First-principles calculations of NMR parameters for phosphate materials

Abstract

In this short review, we discuss the ability to reproduce NMR parameters in the case of phosphates materials through electronic structure calculation within density functional theory linear response. Indeed, the gauge-including projector-augmented wave is today largely used by the solid-state NMR community as a tool for structural determination and it has been applied to a large variety of materials. We emphasise on the crucial points that should be taken into account to perform such calculations. In particular, we discuss the influence of the electronic structure and of the geometry on the calculation of NMR parameters. To illustrate the review, we present experimental and theoretical comparison of (31)P, (1)H and (23)Na NMR data on a series of sodium phosphate systems.

Is the 31P chemical shift anisotropy of aluminophosphates a useful parameter for NMR crystallography?

“…Conversely, the sensitivity of the NMR parameters to small changes in structure could enable different structural models or proposals to be validated or refined, if the NMR parameters could be accurately predicted and compared with experiment. Recent work has shown that periodic DFT calculations can successfully predict 31 P and 27 Al NMR parameters for AlPOs (following appropriate optimization, as discussed in detail by Sneddon et al). In this work, crystal structures were taken from the literature (see Table ) and optimized as described above.…”

“…It is often necessary to optimize the geometry to an energy minimum in order to obtain good agreement with experimental NMR spectra . The use of semiempirical dispersion‐correction (SEDC) schemes has been demonstrated to have a significant impact on the longer‐range structures obtained after DFT optimization for calcined and as‐prepared AlPOs, with structures optimized using SEDC schemes having better agreement between calculated and experimental NMR and XRD parameters …”

Computational and Experimental 1H-NMR Study of Hydrated Mg-Based Minerals

“…where σ re f is the chemical shielding tensor for a reference compound. It has been established that the DFT gauge-including projector augmented wave (GIPAW) method (used here) has a linear relationship between the variation in the experimental (δ exp ) and calculated chemical shifts δ calc [36], and that σ exp re f and σ calc re f are not necessarily equivalent. This linear variation is given by…”

Ab initiocomputation for solid-state31P NMR of inorganic phosphates: revisiting X-ray structures

“…12 The GIPAW approach was first used for NMR spectral assignments by Profeta and coworkers in silicates 13 and has since been applied to a wide range of organic and inorganic compounds, including sodium perovskites, 14 organic solids, 15,16 aluminum oxides, 17 and phosphates. [18][19][20][21][22][23][24][25][26]…”