Quantum calculation of inelastic neutron scattering spectra of a hydrogen molecule inside a nanoscale cavity based on rigorous treatment of the coupled translation-rotation dynamics

HD in C 60 : theoretical prediction of the inelastic neutron scattering spectrum and its temperature dependence

“…They were performed using the sophisticated methodology for calculating the INS spectra of a hydrogen molecule inside a nanoscale cavity, which has been introduced by us recently [17,18]. The extension of the methodology to heteronuclear guest molecules such as HD, which was required for the computations in this work, has also been presented [26].…”

“…The INS spectroscopy has so far provided only very limited experimental information about this interesting system [15,16]. Therefore, the predicted spectra which have emerged from this study should be very valuable for future INS investigations of HD@C 60 [17].…”

“…The methodology for accurate and efficient quantum calculation of the INS spectra, both the energies and intensities of the transitions, of a hydrogen molecule confined inside a nanoscale cavity has been introduced recently [17]. It uses the five-dimensional T-R eigenstates of the Hamiltonian in equation (2.1) as the initial and final states of the INS transitions.…”

“…Recently, we have developed the quantum methodology that achieves this goal by fully including the T-R coupling [17,18]. It allows rigorous quantum simulation of the INS spectra, i.e.…”

“…the energies and the intensities of the INS transitions, of a hydrogen molecule confined inside a nanoscale cavity with an arbitrary shape. The distinguishing feature and the main strength of our approach is its incorporation of the coupled quantum fivedimensional T-R energy levels and wave functions of the entrapped hydrogen molecule as the initial and final states of the INS transitions [17,18]. As a result, the simulated INS spectra fully capture the intricacies of the T-R dynamics of the guest molecule in nanoconfinement and are exceptionally realistic, as demonstrated by the excellent agreement between the calculated and measured INS spectra of p-and o-H 2 inside the small cage of the structure II clathrate hydrate [17].…”