Internal axis molecular parameters, torsional energies and matrix elementsof methyl mercaptan-D-2

In this paper an internal axis method Hamiltonian model has been applied to evaluate the torsional-rotational molecular parameters of asymmetrically s ubstituted methyl mercaptan (CHD2SH) using previously observed microwave tr ansitions. The torsional potential barrier function V-2 has been obtained. The pure torsional energies and matrix elements between various torsional s ub-levels up to the fourth excited torsional state in the ground vibrationa l state hale been determined. The matrix elements and the torsional energie s will be of great value to researchers seeking the spectrum of this molecu le. (C) 2000 Elsevier Science B.V. All rights reserved.