MOLECULAR CONSTANTS FOR $CO_{2}$ AND ITS ISOTOPIC SPECIES FROM HETERODYNED LASER DATA

Author Institution: Department of Physics, The Ohio State University; Massachusetts Institute of Technology, Lincoln Labortory Lexington, Massachusetts 02173. ; Massachusetts Institute of Technology, Lincoln Labortory Lexington, Massachusetts 02173.Molecular constants of $^{12}$C$^{16}$O$_{2}$, $^{13}$C$^{16}$O$_{2}$ $^{12}$C$^{18}$O$_{2}$ and $^{13}$C$^{18}$O$_{2}$ for the Fermi diad ($10^{0}0, 02^{0}0$) were obtained using the absolute frequencies measured from laser heterodyne $techniques.^{1}$ The constants were evaluated by a numerical iterative procedure in which the rotational dependent part of the Fermi coupling element, $\delta$J(J + I), was included. The theoretical relations for isotopic substitution for this molecule are well satisfied