Embedded Mean-Field Theory for Solution-Phase Transition-Metal Polyolefin Catalysis.

Increasing the wall-clock-time efficiency of quantum mechanics/molecular mechanics (QM/MM) calculations without sacrificing accuracy is crucial to the cost-intensive simulation of solution-phase dynamical processes. In this work, we introduce the use of embedded mean-field theory (EMFT) as the QM engine in the QM/MM molecular dynamics (MD) simulations to examine polyolefin catalysts in solution. We show that employing EMFT in this mode preserves the accuracy of hybrid-functional DFT in the QM region while providing up to 20-fold reductions in the cost per SCF cycle, thereby increasing the accessible simulation time-scales. We find that EMFT reproduces DFT-computed binding energies and optimized bond lengths to within chemical accuracy, as well as consistently ranking conformer stability. Furthermore, solution phase EMFT/MM simulations provide insight into the interaction strength of strongly coordinating and bulky counter-ions.