The extensive thermal emission spectrum attributed to the diatomic bromides of calcium, strontium and barium has been observed in the visible region at temperatures about 2200–2400° C, using a vacuum graphite furnace. Many new bands,viz., 141 in CaBr, 53 in SrBr and 68 in BaBr, have been recorded and classified. The vibrational constants agree with those determined by earlier workers and involved the ground state in each case. The transition C→X apears in each molecule and consists of two equally intense systems,viz., C₁→X and C₂→X. The general spectroscopic features of the C→X systems of the bromides of the II A sub group of the periodic table have been compared. They exhibit a close structural similarity and furnish a good example of homologous spectra. The system C→X in all these molecules arises from a C²π−X²Σ⁺ transition where the²π state appears to be intermediate between Hund’s cases (a) and (b).

Thermal emission spectrum of NiBr molecule excited by vacuum graphite tube furnace revealed the existence of ten new band sub-systems in the region λλ 5540-4720 Å which were attributed toA→X,B→X,C→X andD→X transitions. Vibrational analysis was carried out for each of the systems mentioned above.A² Δ has been suggested as the ground state of NiBr molecule with an electronic interval of about 533 cm⁻¹. Transitions responsible for NiBr spectrum appear to be of the type²π–²Δ and²Δ–²Δ.

Thermal emission spectrum of YbI molecule has been photographed for the first time in the spectral regionλλ 6100–6400 Å using Saha’s high temperature furnace at a reciprocal linear dispersion of 7.3 Å/mm. A total of 52 single-headed and violet degraded bands have been recorded and are classified into a single system. Vibrational analysis has been carried out and it has been suggested that system arises from the ground state with the vibrational constantω″_e=153.0 cm⁻¹.

Thermal emission spectrum of MnSe molecule, excited in high temperature graphite furnace, has been photographed in the spectral region λλ4150–5800 Å at a reciprocal linear dispersion of 7.3 Å/mm. The study reveals the presence of two band systems viz.A–X andB–X in whichB–X is entirely new. While the systemA–X consists of 29 bands, the new systemB–X comprises of 24 single headed and red degraded bands. Vibrational analysis performed suggested that both the systems involve ground state⁶Σ with a vibrational frequencyω″_e=361.0 cm⁻¹. Transition responsible for MnSe spectrum appears to be of the type⁶Σ–⁶Σ.

An estimation of the ground state vibrational frequency for MnTe molecule gives rise to its value as 280 cm⁻¹.