On The Low-Frequency Vibrational Modes of C 60
Abstract
The vibrational spectrum of C
60
is compared to the spectrum of a classical isotropic elastic spherical shell. We show correlations between the low frequency modes of C
60
and those of the spherical shell. We find the spherical model gives the approximate frequency ordering for the low frequency modes. We estimate a Poisson ratio of
σ≈0.30
and a transverse speed of sound of
v
s
≈1800
m/s for the equivalent elastic shell. We also find that
ω(
M
1
)/ω(
M
0
)=
3
2
−
−
√
for the shell modes
M
0
and
M
1
, independent of elastic constants. We find that this ratio compares favorably with an experimental value of 1.17.