Towards energy decomposition analysis for open and closed shell f-elements mono aqua complexes

Polarization energy of the [Lr–OH2]3+ dimer systems as calculated with both a small and large core pseudopotential as a function of the Lr–OH2 distance. [Display omitted] ► Energy decomposition analysis of lanthanide and actinide monoaqua systems. ► Open-shell and closed-shell complexes. ► Comparison of large f-in-core or small core quasi relativistic pseudopotentials. ► Computation of the unpaired electrons contribution to the polarization energy component. We propose an energy decomposition analysis of mono aqua systems of both open and closed shell lanthanide and actinide cations using the CSOV scheme. We compared the values obtained with either large f-in-core or small core quasi relativistic pseudopotentials and computed the unpaired electrons contribution to the polarization energy component. Through a quasi-systematic approach on a number of chosen f-element cations, we quantified the different trends across both series for each contribution. This work is an important preliminary step for the acquisition of reference ab initio data for further parameterization of polarizable force fields for lanthanides and actinides.