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We present an extension of the equation-of-motion coupled-cluster singles and doubles (EOM-CCSD) theory for computing x-ray L-edge spectra, both in the absorption
(XAS) and photoelectron (XPS) regimes. The approach is based on the perturbative evaluation of spin-orbit couplings using the Breit-Pauli Hamiltonian and nonrelativistic wave-functions described by the fc-CVS-EOM-CCSD ansatz (EOM-CCSD
within the frozen-core core-valence separated (fc-CVS) scheme). The formalism is
based on spinless one-particle density matrices. The approach is illustrated by modeling
XAS and XPS of several model systems ranging from argon atoms to small molecules
containing sulfur and silicon.