High throughput screening of norbornadiene/quadricyclane derivates for molecular solar thermal energy storage.

We present a procedure for performing high throughput screening of molecular compounds for molecular solar thermal energy storage devices using extended tight binding (xTB) methods. In order to validate our approach, we performed screening of 3230 norbornadiene/quadricyclane (NBD/QC) derivatives in terms of storage energies, activation barriers and absorption of solar radiation using our approach, and compared it to high level density functional theory (DFT) and cluster perturbation (CP) theory calculations. Our comparisons show that the xTB screening framework correlates very well with DFT and CP theory in that it predicts the same relative trends in the studied parameters although the storage energies and thermal reaction barriers are significantly offset. Utilizing the screening methodology, we have been able to locate compounds that would either be excellent candidates or compounds that should not be considered further for molecular solar thermal energy storage devices. This methodology can readily be extended and applied to screening other molecular motifs for molecular solar energy storage.