Atomistic modeling of $[\mathrm{W}_{18}\mathrm{O}_{54}(\text{SeO}_{3})_{2}]^{4-}$ polyoxometalates (POM) molecules in the presence of counter-cations

Polyoxometalates (POMs) are versatile molecular metal oxides explored for various applications. This case study focuses on
$[\mathrm{W}_{18}\mathrm{O}_{54}(\text{SeO}_{3})_{2}]^{4-}$
, a POM with potential for integration with molecular memory devices. The impact of counter-cations on its properties is investigated using Density Functional Theory (DFT). The study delves into the computational details of
$[\mathrm{W}_{18}\mathrm{O}_{54}(\text{SeO}_{3})_{2}]^{4-}$
optimization using DFT, considering counter-cations and solvents. Theoretical models reveal the significant influence of counter-cations on frontier orbital energies, especially in vacuum. Interestingly, the Continuum Solvent Model (COSMO) demonstrates that explicit counter-cations have a minor impact when solvents are considered. This finding has implications for computational efficiency in future POM studies. The study concludes by highlighting the importance of counter-cations in DFT modelling and proposes avenues for further research, including expanding the range of POMs and exploring POM-cation-surface interactions.