A new approach for glass NMR structural studies: in silico NMR spectrocopy approach
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, 68–69, 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.
