Fig. 4: The anharmonicity and phonon localization in MH-III. | Nature Communications

Fig. 4: The anharmonicity and phonon localization in MH-III.

From: Pressure-regulated rotational guests in nano-confined spaces suppress heat transport in methane hydrates

Fig. 4

a, b The potential energy surface of the CH4 molecule at 3 GPa with respect to its rotation about different axes: (a) C–H vector; (b) parallel to the a-axis. The dashed lines are quadratic harmonic fittings at energy minimum. The inset in (a) shows the potential energy surface at 60 GPa when the CH4 molecule does quasi-harmonic librational motions about the C–H vector. c, d Phonon participation ratio (PPR) spectra for the all-atom model (black lines), the point-mass model (red lines), and the fictitious zero-torque model (gray lines) at (c) 3 GPa and (d) 60 GPa. The dashed lines mark PPR values = 0.2 and 0.4 for comparisons. Source data are provided as a Source Data file.

Back to article page