DFT Computations in NMR and MD simulations of glass
A new approach for glass NMR structural studies: in silico NMR spectrocopy approach
DFT Computations in NMR and MD simulations of glass

Polarizable force-fields were developed for modelling aluminosilicate glasses including aspherical shape of the ions. Comparison of the computed 17O MQMAS NMR spectra shows unprecedented agreement with experimental data, both in spectra (left) and in the T-O-T’ population variation with the compositions (right).

                DFT computation of NMR parameters with specific methods for solids, i.e., with periodic boundary conditions, have now become essential in solid-state NMR studies.[1,2] We are developing integrated methodologies  based on the combination of molecular dynamics simulations with NMR to help the detailed interpretation of experimental data for glasses.[3] We applied them to aluminosilicate glasses to improve our understanding of the local structural features controlling the NMR parameters of nuclei like 27Al, 29Si, 23Na, 43Ca[4-6] or rare-earth elements such as Y+++ and Sc+++.[7] We have shown the importance of polarization effects in the design of force fields (fitted to DFT) for significantly improving the mixing between network formers (Al/Si) as unambiguously determined by oxygen-17 NMR.[8] Polarizable force-fields has been developed for simple ternary SiO2-B2O3-Na2O borosilicate glasses[9] and currently extended to more complex glass compositions.

Recent References

[1] Charpentier, T. The PAW/GIPAW Approach for Computing NMR Parameters: A New Dimension Added to NMR Study of Solids. Solid State Nucl. Magn. Reson. 2011, 40 (1), 1–20.
[2] Pickard, C. J.; Mauri, F. All-Electron Magnetic Response with Pseudopotentials: NMR Chemical Shifts. Phys. Rev. B 2001, 63 (24), 245101.
[3] Charpentier, T.; Menziani, M. C.; Pedone, A. Computational Simulations of Solid State NMR Spectra: A New Era in Structure Determination of Oxide Glasses. RSC Adv. 2013, 3 (27), 10550.
 
[4] Gambuzzi, E.; Pedone, A.; Menziani, M. C.; Angeli, F.; Caurant, D.; Charpentier, T. Probing Silicon and Aluminium Chemical Environments in Silicate and Aluminosilicate Glasses by Solid State NMR Spectroscopy and Accurate First-Principles Calculations. Geochim. Cosmochim. Acta 2014, 125, 170–185.
[5] Gambuzzi, E.; Pedone, A.; Menziani, M. C.; Angeli, F.; Florian, P.; Charpentier, T. Calcium Environment in Silicate and Aluminosilicate Glasses Probed by 43Ca MQMAS NMR Experiments and MD-GIPAW Calculations. Solid State Nucl. Magn. Reson. 2015, 6869, 31–36.
[6] Gambuzzi, E.; Charpentier, T.; Menziani, M. C.; Pedone, A. Computational Interpretation of 23 Na MQMAS NMR Spectra: A Comprehensive Investigation of the Na Environment in Silicate Glasses. Chem. Phys. Lett. 2014, 612, 56–61.
[7] Jaworski, A.; Charpentier, T.; Stevensson, B.; Edén, M. Scandium and Yttrium Environments in Aluminosilicate Glasses Unveiled by 45Sc/89Y NMR Spectroscopy and DFT Calculations: What Structural Factors Dictate the Chemical Shifts? J. Phys. Chem. C 2017.
 
[8] Ishii, Y.; Salanne, M.; Charpentier, T.; Shiraki, K.; Kasahara, K.; Ohtori, N. A DFT-Based Aspherical Ion Model for Sodium Aluminosilicate Glasses and Melts. J. Phys. Chem. C 2016, 120 (42), 24370–24381.
[9] Pacaud, F.; Delaye, J.-M.; Charpentier, T.; Cormier, L.; Salanne, M. Structural Study of Na2O–B2O3–SiO2 Glasses from Molecular Simulations Using a Polarizable Force Field. J. Chem. Phys. 2017, 147 (16), 161711.

 

 

Maj : 15/06/2018 (1911)

 

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