Abstract. -In this paper we present calculated fractional abundances in dense interstellar clouds for selected atomic and molecular species using three different homogeneous, pseudo-time-dependent models discussed by Bettens, Lee, & Herbst (1995): the new standard model, the new neutral-neutral model, and model 4. We have run each model with 3 different hydrogen densities -10 3 , 10 4 , and 10 5 cm −3 -and two temperatures -10 K and 50 K. "Low metal" elemental abundances have been used for all three models; the new standard model has also been run with "high metal" abundances.