The energy states and optical spectra of heavily doped mixed crystals are investigated. Studies are
made for the following binary systems: (1) naphthalene-h8 and -d8, (2) naphthalene-h8 and -ad1, and (3)
naphthalene-h8 and -bd1 , corresponding to strong, medium, and weak perturbations, respectively. In
addition to ordinary absorption spectra at 4°K, band-to-band transitions at both 4 and 77°K are also
analyzed with emphasis on their relations to cooperative excitation and over-all density-of-states functions
for mixed crystals. It is found that the theoretical calculations presented in a previous paper agree generally
with experiments except for cluster states observed in system (1) at lower guest concentrations. These
features are discussed semiquantitatively. As to the intermolecular interaction parameters, it is found
that experimental results compare favorably with calculations based on experimental density-of-states functions
but not with those based on octopole interactions or charge-transfer interactions. Previous experimental
results of Sheka and the theoretical model of Broude and Rashba are also compared with present investigations
