J-dependence of self-, H2- and He-broadened linewidth parameters for l-type doublet transitions in the bending vibrational state (0110) of HCN

Study of T1-and T2-Relaxation by Microwave Pulse Techniques: Rotational Transition J=0-1 of HCCF,J-Dependence of Rotational Transitions of S02,and l-Type Doublet Transitions of HC15N Perturbed by Self, H2, D2, and He

“…Table 1 con tains the results for the rotational transition J = 0 -1 of HCCF in the pure gas and for /-type doublet transi tions in the (Ol^-state of HC15N with J = 9 and J = 10 in the pure gas and mixtures with H2, D2 and He. The Table gives puted from the theory proposed earlier [10]. Table 2 gives the experimental results for seven rotational transitions of S 0 2 in the pure gas.…”

“…For the computation of inelastic rate constants which enter into expression (57) for 1/T1; the normalization procedure as proposed earlier [10] has been used except for the results indicated with sub script (*) where the value of Nt is chosen to be 1 in (A 8) of [10]. The molecular parameters for HC15N, H2 and He are given in [10]. The rotational constant for D2 is given by 917.87 GHz [31], and all other parameters used were the same as for H2.…”

“…This indicates the limitations of the exponential approximation for the non-diagonal matrix elements of the time development operator in [10]. Thus, to understand the observed differences between the T1-and T2-rates more quantitatively, a nonperturbative approach or higher order perturbation treatment of collisional scattering dynamics is essential.…”

“…Second order dipole-type collisional transitions would contribute to collisions of type (i), which will make the value of 1 /Tt smaller than the corresponding value of 1 /T2. Inadequacies of pre vious first order perturbative approaches to binary collision theory have also been found during recent investigations on the pressure dependence of 1 /T2-rates for various /-type doublet transitions of HC15N, exhibiting significant differences between theoretical and experimental results [10].…”

Centrifugal Distortion Analysis and Study of T 2 -Relaxation for l-Type Doublet Transitions of Nitrous Oxide ( 15N2O) by a Microwave Pulse Technique

“…Pressure broadening parameters for /-type doublet transitions have been determined rarely [1][2][3][4][5][6] in the microwave region. The investigation of pressure broadening parameters of /-type doubling transitions is useful in addition to the investigation of the selfbroadening of pure rotational lines because these studies provide additional information about rotational relaxation caused by differences of collision-induced energy transfer involved in the two types of transitions.…”