THE MAGNETIC ROTATION SPECTRUM OF FORMALDEHYDE: SINGLET-TRIPLET PERTURBATIONS IN VIBRONIC LEVELS OF THE $\tilde{A}^{1}A_{2}$ STATE OF $H_{2}CO$

$^{1}$ D.A. Ramsay and S.M. Till, Can. J. Phys. 57, 1224 (1979).Author Institution:Magnetic rotation spectra of the $2^{1}_{0} 4^{1}_{0}, 2^{1}_{0} 4^{3}_{0}, 2^{2}_{0} 4^{3}_{0}$ and $2^{3}_{0}4^{1}_{0}$ bands of the $\tilde{A}^{1}A_{2} - \tilde{X}^{1}A_{1}$ system of formaldehyde have been photographed under high resolution. Several lines in the magnetic rotation spectrum have been correlated with singlet-triplet perturbations in the excited state in the same manner as has been reported for the $4^{1}_{0}$ and $4^{3}_{0}$ $bands^{1}$. The detailed analyses of the new perturbations will be discussed