Abstract: A computerized molecular modeling system is provided which graphically displays at least an initial and most likely structure of a molecule utilizing energy minimization and/or molecule dynamics techniques. The system utilizes a sensitivity factor to determine how often the less sensitive interactions, especially non-bonded interaction in a molecule should be recalculated during an energy minimization or molecular dynamics procedure. The sensitivity factor is based on each interaction's sensitivity to changes in the positions of the atoms that comprise it.

Abstract: Purified aromatic dicyanates are cured with a catalyst which is an Mn(II), Ag(II), Fe(III), Bi(III), In(III) or Hf(IV) salt at 150.degree.-200.degree. C. and then at 200.degree.-300.degree. C. for a time sufficient to cure the dicyanate without causing color formations to the extent of a Yellowness Index over 30. In some forms the dicyanate is combined with the catalyst and a thermoplastic.

Abstract: A monomeric aromatic dicyanate is purified to remove color forming impurities, combined with a zinc salt catalyst and cured first below 200.degree. C. and then for a limited time at or above 200.degree. C., either alone or in admixture with or on a thermoplastic polymer. For example, purified 2,2-bis(4-cyanatophenyl)propane is purified, combined with a poly(ester carbonate) and zinc chloride, and then cured at increasing temperatures from 150.degree. C. to 250.degree. C.