H2O inside the fullerene C60: Inelastic neutron scattering spectrum from rigorous quantum calculations

Minzhong Xu; Peter M Felker; Zlatko Bačić

doi:10.1063/5.0086842

H₂O inside the fullerene C₆₀: Inelastic neutron scattering spectrum from rigorous quantum calculations

J Chem Phys. 2022 Mar 28;156(12):124101. doi: 10.1063/5.0086842.

Authors

Minzhong Xu¹, Peter M Felker², Zlatko Bačić¹

Affiliations

¹ Department of Chemistry, New York University, New York, New York 10003, USA.
² Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, USA.

PMID: 35364860
DOI: 10.1063/5.0086842

Abstract

We present a methodology that, for the first time, allows rigorous quantum calculation of the inelastic neutron scattering (INS) spectra of a triatomic molecule in a nanoscale cavity, in this case, H₂O inside the fullerene C₆₀. Both moieties are taken to be rigid. Our treatment incorporates the quantum six-dimensional translation-rotation (TR) wave functions of the encapsulated H₂O, which serve as the spatial parts of the initial and final states of the INS transitions. As a result, the simulated INS spectra reflect the coupled TR dynamics of the nanoconfined guest molecule. They also exhibit the features arising from symmetry breaking observed for solid H₂O@C₆₀ at low temperatures. Utilizing this methodology, we compute the INS spectra of H₂O@C₆₀ for two incident neutron wavelengths and compare them with the corresponding experimental spectra. Good overall agreement is found, and the calculated spectra provide valuable additional insights.