Ab initio calculations of forbidden transition amplitudes and lifetimes of the low-lying states in V4+

We report electric quadrupole (E2) and magnetic dipole (M1) transition amplitudes of the first few low-lying states of quadruply ionized vanadium (V4+), which are important in various experimental applications and astrophysics. To our knowledge, most of these presented results are determined for the first time in the literature. A relativistic multireference Fock-space coupled-cluster theory with single (S), double (D), and partial triple (T) excitations is employed to compute the forbidden transition probabilities and lifetimes of the low-lying states in V4+. Estimations of different correlation effects arising through the above formalism have been highlighted by investigating core and valence electron excitations. A long lifetime is found for the first excited 3d D 5 2 2 state, which suggests that V4+ may be one of the useful candidates for many important studies. © 2007 The American Physical Society.