Infrared emission spectrum of neutral vanadium (V i)*†

The first spectrum of vanadium has been observed in the 1.0–5.6 μm extraphotographic infrared region by means of Fourier spectroscopic techniques. These observations have produced measurements for about 450 infrared V i lines and preliminary analysis has led to a revision and extension of the spectroscopic terms arising from the 3d5 configuration. The 4F term at about 37 000 cm−1 formerly ascribed to 3d5 has been reassigned to 3d44s. The lowest term of the 3d5 configuration, 6S5/2 at 20 202.47 ± 0.05 cm−1 has been reaffirmed by means of high-precision infrared measurements. In addition, three probable new 3d5 terms, 4G at about 34 200 cm−1, 4P at about 33 000 cm−1 and 2F at about 35 700 cm−1 have been tentatively identified.