The Harmonic Picture of Nuclear Mean Kinetic Energies in Heavy Water

6th Workshop in Electron Volt Neutron Spectroscopy: Frontiers and Horizons

Romanelli, G.^1 ; Fernandez-Alonso, F.^2,3 ; Andreani, C.^1,4

Università Degli Studi di Roma Tor Vergata, Dipartimento di Fisica and Centro NAST, via della Ricerca Scientifica 1, Rome

00133, Italy^1

ISIS Facility, Rutherford Appleton Laboratory, Oxfordshire, Chilton, Didcot

OX11 0QX, United Kingdom^2

Department of Physics and Astronomy, University College London, Gower Street, London

WC1E 6BT, United Kingdom^3

Consiglio Nazionale Delle Ricerche, CNR-IPCF, Sezione di Messina, i, Italy^4

关键词: Deep inelastic neutron scattering;    Harmonic model;    Local environments;    Local potentials;    Quantum kinetic;    Short-time dynamics;    Theoretical approach;    Vibrational modes;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/571/1/012003/pdf
DOI  :  10.1088/1742-6596/571/1/012003

来源: IOP

【 摘 要 】

This paper presents a study of the total mean kinetic energy, EK, and of individual projections along a given molecular axis, EKα, for D and O nuclei in D2O, derived using a harmonic model. Our theoretical approach assumes decoupling amongst translational, rotational and vibrational modes. Resulting values of these dynamical quantities are discussed in terms of the anisotropy of the quantum kinetic energy tensor, its relation to the local potential, and deviations from the hypothesis of harmonicity and mode decoupling. Results are compared with corresponding quantities obtained from Deep Inelastic Neutron Scattering experiments performed on liquid and solid D2O, where the short-time dynamics and local environment of D and O atoms were probed. The present study confirms an overall picture where even small changes in the short-range environment of D and O nuclei have a strong influence on the quantum behaviour of heavy water.