Computational Study of the Imaging of a Molecular Crystal with the Atomic Force Microscope

as the molecules approach under the application of pressure. We expect that high-pressure Raman study will provide further insight into the vibrational and bonding properties in solid Cso The pressure behavior of a “squashing” mode, a radial distortion from the spherical shape into an ellipsoid, is particularly interesting in comparison with the softening observed for the IF,, radial mode. A high-pressure Raman measurement is in progress. the largest outward displacement of atoms in the lFl, motion, resulting in attractive forces along the radial axes. The orbital overlapping partly occurs at contacting molecular faces and hence its contribution to the entire molecular vibration is thought to be small. However, the gradual decrease in the frequency of 1 F,, mode suggests that the intermolecular attractive force is strengthened through the increase in the ?r orbital overlapping