Is DFT enough? Towards accurate high-throughput computational screening of azobenzenes for molecular solar thermal applications†

An efficient screening of azobenzene (AB) derivatives for Molecular Solar Thermal (MOST) applications based on ground state properties (energy stored per molecule and Z isomer stability) could be performed with quasi-CASPT2 accuracy. In this work, we show how wavefunction and electron density based methods can be efficiently combined in a computational protocol that yields accurate potential energy profiles with a significant reduction in computational cost compared to that of a fully-CASPT2 characterization. Our results on prototypical electron donor/withdrawing AB derivatives clearly identify pull–pull substitution as the most promising, allowing to draw guidelines for the chemical design of promising azo-MOST candidates.