Introduction:
Accurate atomic data for Ti II are essential for abundance analyses in astronomical objects. The aim of this work is to provide accurate and extensive isotope shift transition (TIS) results for Ti II, specifically by comparing our theoretical calculations with existing experimental measurements and other theoretical predictions.
Methods:
The calculations were performed using two robust multiconfiguration approaches:
The non-relativistic Multiconfiguration Hartree–Fock (MCHF) combined with the Breit–Pauli approximation (MCHF-BP).
The fully relativistic Multiconfiguration Dirac–Hartree–Fock (MCDHF) combined with the Relativistic Configuration Interaction (RCI) method.
These methods were implemented using the ATSP2K (Atomic Transfer and Structure Package) and GRASP2018 (General-purpose Relativistic Atomic Structure Package) codes, respectively.
Results:
Energy levels and isotope shift transitions (TIS) were calculated for the 3d2 4s 4FJ → 3d2 4p 4GJ+1 transitions in Ti II. The calculated excitation energies are found to be in good agreement with the experimental data. We present the results for the isotope shifts (ISs), which are compared extensively with previous theoretical calculations and available experimental measurements. The current theoretical TIS values show, overall, a better agreement with the experimental values than other theoretical predictions, demonstrating the high accuracy of the present work.
Conclusion:
We have performed an extensive comparison of our computed isotope shift transitions (TIS) with existing theoretical and experimental data. Notably, the accuracy of the total isotope shift (TIS) is significantly improved compared to previous theoretical efforts. Our calculated TIS values demonstrate excellent overall agreement with the measured results, confirming the reliability and high quality of the advanced theoretical methods used in this work.
