Assessment of the SCAN Functional for Spin-State Energies in Spin-Crossover Systems

The Strongly-Constrained and Appropriately Normed (SCAN) functional has been tested towards the calculation of spin-state energy differences in a dataset of 20 spin-crossover (SCO) systems, ranging from d4 to d7. The results shown that SCAN functional is able to correctly predict the low-spin state as the ground state for all systems, and the energy window provided by the calculations falls in the approximately range of energies that will allow for SCO to occur. Moreover, because SCAN is a pure meta-GGA functional, one can use such method in periodic calculations, accounting for the effect of collective crystal vibrations and counterions in the thermochemistry of the spin-transition. Our results validate this functional as a potential method for in silico screening of new SCO systems at both, molecular and crystal packed levels