Theoretical study of transition spectra of TiO molecule

The transitional characters for eight transition systems of TiO were investigated by using the ab initio calculation. Highly accurate MRCI + Q approach was used to investigate the potential energy curves (PECs) and transition dipole moment curves (TDMCs) with 4221 levels that results are consisted with experimental determinations. Moreover, combining the values of PECs with TDMCs, the Einstein A coefficients, transitional lifetimes, ro-vibrational intensities, absorption oscillator strengths, and frequency-integrated cross sections are calculated including transition bands v' = 0-6 <- v '' = 0-6. For application in the atmospheres, the absolute intensities and line-shapes of allowed transition systems at different temperature were studied to satisfy some astrophysical applications. The results are also potentially useful for important Astrophysics Data System (ADS) and databases such as HITEMP, NIST. Since the results from many laboratory techniques and our calculations now agree, analyses of TiO based on absorption from allowed transitions are no longer hindered by present determinations. (C) 2020 Elsevier Inc. All rights reserved.