Deuterium-bearing molecules in cold and warm dense interstellar clouds

We have studied the production of key observed deuterium species for TMC-1, Orion, L134N and W3IRS4 clouds, of densities 104, 104, 5 × 104, and 106 cm−3, respectively, by using the pseudo-time dependent gas-phase chemistry. These clouds have temperatures in the range 10–70 K. The main results by using the more extensive chemical network with the most updating reaction rates show that the most of calculated fractional abundances are in agreement with observations, and suggest that triply-deuterated ammonia could be detectable in dark clouds. Also our models show that large abundance of NH2D and NHD2 can be produced in the interiors of cold dense clouds at steady state time.