Changes

The frequencies where absorption lines occur, as well as their relative intensities, primarily depend on the electronic and molecular structure of the molecule. The frequencies will also, though, depend on the interactions between molecules in the sample, the crystal structure (in solids) and on several environmental factors (e.g., temperature, pressure, electromagnetic field). The lines will also have a width and shape that are primarily determined by the spectral density or the density of states of the system.

The frequencies where absorption lines occur, as well as their relative intensities, primarily depend on the electronic and molecular structure of the molecule. The frequencies will also, though, depend on the interactions between molecules in the sample, the crystal structure (in solids) and on several environmental factors (e.g., temperature, pressure, electromagnetic field). The lines will also have a width and shape that are primarily determined by the spectral density or the density of states of the system.