Linear response at the 4-component relativistic level: Application to the frequency-dependent dipole polarizabilities of the coinage metal dimers

The theory, implementation, and application of linear response at the 4-component relativistic closed-shell Hartree-Fock level based on the concept of quasienergy and time averaging are reported. As such, an efficient AO-driven algorithm is obtained by assigning specific Hermiticity and time reversal symmetry to the trial vectors used in the solution of the reduced response equations. The given implementation has a quite general structure and thereby allows the calculation of a wide range of second-order properties such as polarizabilities, magnetizabilities, as well as NMR parameters.