The OCM-2 oligocarbonatemethacrylate was investigated using a HYPERCHE
M 4.0 molecular computer package. We have optimized the geometry of th
e OCM-2 molecule receiving a non-linear structure. Non-uniformly distr
ibuted electron charge densities and multipole moments were obtained f
rom nb initio calculations. The heteropolar C=O double chemical bonds
are transversal with respect to a bent central chain and play an impor
tant role in the formation of the optical and non-linear optical featu
res. We have calculated different HOMO-LUMO energy gaps using semiempi
rical PM3 and ab initio methods for singlet and triplet states and the
best agreement with the optical absorption data was observed for the
PM3 triplet states. One can expect that the OCM-2 electronic structure
properties have strong influence on the solid mixturies, which are fo
rmed on basis of the OCM-2 polymer and analogous compounds. (C) 1997 E
lsevier Science Ltd.