Improving density functional calculations of molecular polarizabilities using locally scaled self-interaction corrections.

The molecular polarizability characterizes the first response of the electronic charge of a molecule placed in a static electric field. From the computational viewpoint, the static polarizabilities are important for predicting intermolecular interactions. In the Kohn–Sham density functional theory (KS–DFT), present day functionals are known to overestimate the molecular polarizabilities. Using a recent benchmark static polarizabilities database, we examine the effect of self-interaction errors (SIE) in the molecular polarizabilities at the level of the local density approximation (LSDA). Our results shows that the Perdew-Zunger scheme with Fermi-LÖwdin orbital self-interaction correction (FLOSIC)¹ methodology leads to underestimated polarizabilities due to overcorrections. However, employing the strategy of scaling down the SI correction term in the recently developed local-scaling self-interaction correction (LSIC)² will result in excellent agreement with the benchmarked values of static polarizabilities.

(1) Yang, Z.-h.; Pederson, M. R.; Perdew, J. P. .Phys. Rev. A2017,95, 052505.
(2) Zope, R. R.; Yamamoto, Y.; Diaz, C. M.; Baruah, T.; Peralta, J. E.; Jackson, K. A.;Santra, B.;
Perdew, J. P. .JCP, 2019,151, 214108.