Excitation energies, polarizabilities, multipole transition rates, and lifetimes in Th IV

Excitation energies of the ns1/2 (n= 7-10), npj (n = 7-9), ndj (n= 6-8), nfj (n= 5-7), and ngj (n= 5-6) states in Th IV are evaluated. First-, second-, third-, and all-order Coulomb energies and firstand second-order Coulomb-Breit energies are calculated. Reduced matrix elements, oscillator strengths, transition rates, and lifetimes are determined for the 96 possible nlj−n′l′ j′ electric-dipole transitions. Multipole matrix elements (7s1/2 − 6dj , 7s1/2 − 5fj , and 5f5/2 − 5f7/2) are evaluated to obtain the lifetimes of the 5f7/2 and 7s1/2 states. Matrix elements are calculated using both relativistic many-body perturbation theory, complete through third order, and a relativistic allorder method restricted to single and double (SD) excitations. Scalar and tensor polarizabilities for the 5f5/2 ground state in Th 3+ are calculated using relativistic third-order and all-order methods. These calculations provide a theoretical benchmark for comparison with experiment and theory.