Spectroscopy of nickel chloride: Identification of the [15.0] 2Π3/2 and [15.0] 2Δ5/2 states

Fourier transform spectroscopy of NiCl: Identification of the [10.3] 4Φ7/2 state

“…The relative intensity for the two systems was approximately 4:1, respectively. The vibrational frequencies of the five low-lying states are all approximately 430 cm À1 [1][2][3], whereas the excited state vibrational frequencies for NiCl that have been observed to date are approximately 395 cm À1 [4][5][6][7][8][9]. Thus, we concluded that the two new bands are a vibrational progression in the excited state.…”

“…The Bernath and Pinchemel groups have identified five states with electronic term energies in the 20 000-25 000 cm À1 range [1][2][3]. In our laboratory five electronic states with term energies in the 9000-15 000 cm À1 range have been observed and identified [4][5][6][7][8][9].…”

“…Only lines due to the strongest NiCl isotopomer, 58 Ni 35 Cl (51.58% abundance), were clearly identified in the 10 168 cm À1 system, although the spectra show additional structure, probably due to other NiCl isotopomers ( 60 Ni 35 Cl [19.87%], 58 Ni 37 Cl [16.50], and 60 Ni 37 Cl [6.35%]). Using the published parameters for the low-lying levels from previous work [1][2][3][4][5][6][7][8][9], we calculated the energy levels F e (J 00 ) and F f (J 00 ), and the values for D 2 F e (J 00 ) and D 2 F f (J 00 ), where D 2 F e (J) = F e (J + 1) À F e (JÀ1), and D 2 F f (J) = F f (J + 1) À F f (J À 1) for all five of the low-lying states. The method of combination differences [13] was used for the observed branches, and indeed, the three observed branches could be assigned definitively as one P-, one Q-, and one R-branch connecting to the A 2 D 5/2 v = 0 state.…”

“…A total of 216 lines were fitted in a least squares fitting program, using a standard polynomial expression [1][2][3][4][5][6][7][8][9] for both the ground and excited states, T = T 0 + B 0 J(J + 1) À D 0 J 2 (J + 1) 2 . All lines were weighted equally in the fit.…”

“…The low-lying electronic states with term energies less than 3000 cm À1 are labeled X 2 P, A 2 D, and B 2 R + [1][2][3][4][5][6][7][8][9]. Excitation of one of the nickel 3d valence electrons to an unoccupied nickel 4s or 4p orbital leads to numerous electronic transitions throughout the visible and near-infrared spectral regions, identified in the literature as System A through to System J [1][2][3][4][5][6][7][8][9][10][11][12]. The Bernath and Pinchemel groups have identified five states with electronic term energies in the 20 000-25 000 cm À1 range [1][2][3].…”