This experiment was aimed at the determination of the dipole moment of the diatomic molecule HC1⁺ (in the ²π½ state). The method was to observe the Stark splitting optically by using a 3.4 meter Jarrell ash spectrograph. The charged diatomic molecule was obtained by passing HCl gas through a LoSurdo discharge tube in which a high electric field was applied; optical plates were obtained from the spectrograph and analysed. Dipole moment of HC1⁺ in the ²π½ state was found to be smaller than 0.8 debye. / Science, Faculty of / Physics and Astronomy, Department of / Graduate