30
P. I. Ravikovitch
Examples of the calculated VDOS for the narrow pore structures of ZIF-4 and ZIF7 are shown in Fig. 3 in comparison with the inelastic neutron scattering (INS) spectra
[11]. The agreement is surprisingly good, especially in the low-frequency region <
~100 cm
−1 , which gives the most contributions to the vibrational entropy.
Vibrational entropy was calculated using the quasi-harmonic approximation [51]:
Fig. 3 Low-frequency vibrations in ZIFs. Calculated vibrational density of states (black lines)
versus inelastic neutron scattering measurements from Ref. [11] (teal lines). In calculations, both
ZIF-7 and ZIF-4 are in their narrow pore structures (V = 6315 A 3 for ZIF-7(np) and V = 3345 A 3
for ZIF-4(np))
P. I. Ravikovitch
Examples of the calculated VDOS for the narrow pore structures of ZIF-4 and ZIF7 are shown in Fig. 3 in comparison with the inelastic neutron scattering (INS) spectra
[11]. The agreement is surprisingly good, especially in the low-frequency region <
~100 cm
−1 , which gives the most contributions to the vibrational entropy.
Vibrational entropy was calculated using the quasi-harmonic approximation [51]:
Fig. 3 Low-frequency vibrations in ZIFs. Calculated vibrational density of states (black lines)
versus inelastic neutron scattering measurements from Ref. [11] (teal lines). In calculations, both
ZIF-7 and ZIF-4 are in their narrow pore structures (V = 6315 A 3 for ZIF-7(np) and V = 3345 A 3
for ZIF-4(np))