  We report the observation of cold Cs Rydberg atom molecules bound at
internuclear separations of R~3-9 um. The bound states result from avoided
crossings between Rydberg atom pair interaction potentials in an applied
electric field. The molecular states can be modified by changing the applied
electric field. The molecules are observed by mapping the radial separation of
the two Rydberg atoms as a function of time delay between excitation and
detection using the Coulomb repulsion of the ions after pulsed field
ionization. Measurements were performed for 63D+65D, 64D+66D, 65D+67D, and
66D+68D pairs. The experiment is in good agreement with calculations of the
pair interactions for these states.
