Allowed and forbiddenn=2-2 transitions of highly ionised titanium

Relativistic intermediate-coupling wavefunctions are used to evaluate transition energies, line strengths and transition probabilities for all allowed and forbiddenn=2-2 transitions for beryllium-like titanium ion. We have shown that to achieve a better than 1% agreement between theory and experiment for transition energies between then=2-2 levels it is not sufficient to use the three-configuration basis composed of 2s ², 2s2p and 2p ².