Physical chemistry and theoretical chemistry have advanced over the pa
st 50 years from being largely qualitative to having a mature status b
ased firmly on the principles of quantum and statistical mechanics. My
interest in the chemical elements and their compounds has prompted me
to learn more about the nature of matter through the measurement and
interpretation of optical, electric, and magnetic properties of molecu
les. In addition to holding intrinsic interest, such properties tell u
s about charge and current distributions and form the basis of electro
-optics, magneto-optics, and nonlinear optics. They also help us under
stand the nature and strength of long-range intermolecular forces, the
hydrogen bond, and molecular biology-topics that are apparently forev
er young.