E2-transition probabilities for NiXVIII

Accurate theoretical data for the transition probabilities are highly demanding in astrophysics and in the study of plasma in astrophysical objects and fusion devices. Na-like highly stripped ions of iron group, specially NiXVIII is very important in this respect. A highly improved basis in a relativistic many-body coupled-cluster method (CCM) to include correlation properly is employed to calculate excitation energies, the electric quadrupole (E2) transition line strengths and transition probabilities for NiXVIII. The effect of correlation is studied thoroughly. The present improved data for different atomic/ionic properties are compared with the available theoretical and/or experimental data and they are in agreement. Some E2 transition data are reported for the first time.