Microwave spectroscopy of CD₃SH in the ground state

There are many sulfur-containing molecules identified in interstellar medium. However, methyl mercaptan (methanethiol, CH₃SH) is so far, the only confirmed complex organic molecule and further study on its isotopologues would be worthwhile. With the aid of the new high-sensitivity telescopes, it may be possible to detect CD₃SH since CD₃OH was already detected. The rest frequencies of CD₃SH are indispensable information. In the present study of CD₃SH in the ground state, 484 A-species transitions and 581 E-species transitions up to J = 46 and K_a = 10, were least-squares-analyzed by using the pseudo-principal axis method (PAM) Hamiltonian with 22 parameters consisting of rotational, centrifugal distortion, and internal-rotational constants.