In molecular vibrational spectroscopy, a hot band is a band centred on a hot transition, which is a transition between two excited vibrational states, i.e. neither is the overall ground state. In infrared or Raman spectroscopy, hot bands refer to those transitions for a particular vibrational mode which arise from a state containing thermal population of another vibrational mode. For example, for a molecule with 3 normal modes, and, the transition ←, would be a hot band, since the initial state has one quantum of excitation in the mode. Hot bands are distinct from combination bands, which involve simultaneous excitation of multiple normal modes with a single photon, and overtones, which are transitions that involve changing the vibrational quantum number for a normal mode by more than 1.
Read more about Hot Band: Vibrational Hot Bands, Combination Bands
Famous quotes containing the words hot and/or band:
“We should be careful to get out of an experience only the wisdom that is in it—and stop there; lest we be like the cat that sits down on a hot stove-lid. She will never sit down on a hot stove-lid again—and that is well; but also she will never sit down on a cold one anymore.”
—Mark Twain [Samuel Langhorne Clemens] (1835–1910)
“Nothing makes a man feel older than to hear a band coming up the street and not to have the impulse to rush downstairs and out on to the sidewalk.”
—Robert Benchley (1889–1945)