  We have developed one electron detachment theory from a closed-shell atomic
configuration in the relativistic Fock-space coupled-cluster ansatz. Using this
method, we determine sensitivity coefficients to the variation of the fine
structure constant in the first three important low-lying transitions of the
astrophysically interesting highly charged Mn IX, Fe X, Co XI and Ni XII ions.
The potential of this method has been assessed by evaluating the detachment
energies of the removed electrons and determining lifetimes of the atomic
states in the above ions. To account the sensitivity of the higher order
relativistic effects, we have used the four component wave functions of the
Dirac-Coulomb-Breit Hamiltonian with the leading order quantum electrodynamics
(QED) corrections. A systematic study has been carried out to highlight the
importance of the Breit and QED interactions in the considered properties of
the above ions.
