Toward a fast evaluation of g-tensor of Cu containing systems: A DFT parametrized approach

DFT has been applied to evaluate electron paramagnetic resonance (EPR) g-tensor components of copper containing systems using an effective Spin–Orbit operator relying on the use of effective nuclear charges (Zeff). In particular, an optimal Zeff value was obtained for the copper atom by fitting the results obtained for a series of twenty copper bioinorganic complexes to the data obtained, at the same level of theory, using more refined approaches to evaluate Spin–Orbit Coupling terms. We showed that spin–orbit effects can be well approximated using the Zeff method giving reliable g-tensor values at low computational cost for large molecular compounds.