Pressure dependence of the Raman spectra of salts of hexahydridoruthenate(II), M2RuH6 (M=Ca, Sr, Eu) and their deuteride analogues

First-principles study of the pressure dependence of the structural and vibrational properties of the ternary metal hydrideCa2RuH6

“…INS spectroscopy would allow the observation of all vibrational modes and thus would help further assess the performance of the DFT methods for the description of the complete vibrational spectrum. Despite the lack of such data, the overall very good agreement between our theoretical results and the available experimental data shows that DFT can be reliably used to study the pressure dependence of the properties of Ca 2 RuH 6 .…”

“…6 Figure 1 summarizes the resulting theoretical pressure dependences of the Ru-H bond length and of the cell parameter a / 4. Both LDA and GGA calculations predict the same behavior: the two parameters, a / 4 and the Ru-H bond length, are decreasing functions of the pressure.…”

“…In both cases, the pressure dependence is close to linear as experimentally observed for the A 1g ͑ 9 ͒ and T 2g ͑ 5 ͒ modes. 6 Experimentally, 9 is shown to exhibit a strong pressure dependence ͓͑d 9 / dP͔ expt = 17.43 cm −1 / GPa͒, which is more pronounced than the calculated behavior ͓͑d 9 / dP͔ GGA = 5.96 cm −1 / GPa and ͓d 9 / dP͔ LDA = 4.15 cm −1 / GPa͒. On the other hand, the calculated pressure variation of 5 shows a good agreement with the experimental behavior ͓͑d 5 / dP͔ expt = 9.49 cm −1 / GPa, ͓d 5 / dP͔ GGA = 11.44 cm −1 / GPa, and ͓d 5 / dP͔ LDA = 10.75 cm −1 / GPa͒.…”

“…In this regard, a pressure-dependent Raman study on M 2 RuH 6 ͑M =Ca,Sr,Eu͒ has been recently reported. 6 In the present study, we aim to theoretically study the effect of pressure on one of these compounds, namely, Ca 2 RuH 6 , using periodical calculations within DFT. [7][8][9] More specifically, we will investigate the pressure dependence of the structure and of the vibrational properties of Ca 2 RuH 6 , and will compare our results with experimentally available data.…”

“…[7][8][9] More specifically, we will investigate the pressure dependence of the structure and of the vibrational properties of Ca 2 RuH 6 , and will compare our results with experimentally available data. 6 Prior to this, we will discuss the properties of the title compound at ambient pressure. This will be done on the basis of the results of calculations carried out at zero pressure and on the basis of experimental data that will include the results of new Raman spectroscopy measurements performed at ambient pressure on Ca 2 RuH 6 and Ca 2 RuD 6 samples.…”