Knowledge Bank

Saturation Stark spectra of $\mathrm{<mrow\; data-mjx-texclass="ORD">18</mrow>}OCS,O13CS$ and $OC34S$ have been recorded with our intracavity $CO2$ laser spectrometer. The following transitions are reported: $02\circ C\leftarrow 00\circ O,031O\leftarrow 011O,12\circ O\leftarrow 10\circ O,04\circ O\leftarrow 02\circ O,042O\leftarrow 022O,131O\leftarrow 111O,051O\leftarrow 031O$ and $053O\leftarrow 033O$ This amount of quite accurate measurements has allowed for the first time to perform a global rovibrational analysis of those three principal isotopic species of carbonyl sulfide separately. For each of them, any available zerofield and Stark data has been used. Any off diagonal terms of the Harniltonian ($\ell$-type, anharmonic, stark and polarzability) are considered simultaneously and energy matrices are diagonalized in a one step procedure. A lot of high order parameters are fixed to their values determined for normal ocs. The important effect of anharmonic resonances on the effective dipole moments has been established. The equilibrium parameters of carbonyl sulfide deduced from our analysis will be discussed.