XXV CONGRESSO DELLA SOCIETA' CHIMICA ITALIANA - ABSTRACT FORM
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Solid State NMR spectra and GIPAW
plane-wave investigation of
hydrogen storage materials
Roberto Gobetto, Federico Franco, Michele Chierotti, Carlo Nervi,
Marcello Baricco
Department of Chemistry and NIS, University of Turin, via P. Giuria 7, 10125 Torino, Italy
roberto.gobetto@unito.it
An integrated experimental-theoretical approach for the SSNMR investigation of a series of Group I and II metal hydrides and borohydrides, such as NaH, LiH, NaBH4, MgH2, CaH2, Ca(BH4)2 and LiBH4, is reported, mainly focusing on the
computation of the 1H, 23Na, 11B, and 6Li SSNMR parameters by means of the
GIPAW method for these systems, thus aiming to check the reliability of the approach for modelling of NMR spectra. Periodic lattice calculations were performed by using the plane-wave method, as implemented in the Quantum Espresso package (v. 4.3.2). Projector Augmented Wave (PAW), including the Gauge-Including Projected Augmented-Wave (GIPAW) method [1] for SSNMR calculations was used, using both Rappe-Rabe-Kaxiras-Joannopoulos (RRKJ) ultrasoft pseudopotentials (PP) and new developed pseudopotentials.
This new set of PAW PP was validated by comparison not only with experimental data, but also with computed data achieved by employing others sets of PP already available. In particular, the predicted SSNMR 1H, 23Na, and 6Li
chemical shift values obtained by using PAW PP are analogous to those derived by employing the standard PP, whereas the former allows a substantial improvement of the 11B chemical shift estimation. Moreover, our computed
results reproduce the 11B MAS experimental spectrum of commercial Ca(BH 4)2,
distinguishing the two phases (α and β) contained in it [2].
[1] Pickard, C. J.; Mauri, F.; Phys. Rev. B 2001, 63 (24), 245101.
[2] Franco, F.; Baricco, M.; Chierotti, M.R.; Gobetto, R.; Nervi, C. J. Phys. Chem. C 2013, 117, 9991−9998.
Poster
