DFT-CES2: Quantum Mechanics Based Embedding for Mean-Field QM/MM of Solid-Liquid Interfaces.

The solid-liquid interface plays a crucial role in governing complex chemical phenomena, such as heterogeneous catalysis and (photo)electrochemical processes. Despite its importance, acquiring atom-scale information about these buried interfaces remains highly challenging, which has led to an increasing demand for reliable atomic simulations of solid-liquid interfaces. Here, we introduce an innovative first-principles-based multiscale simulation approach called DFT-CES2, a mean-field QM/MM method. To accurately model interactions at the interface, we developed a quantum-mechanics-based embedding scheme that partitions complex noncovalent interactions into Pauli repulsion, Coulomb (including polarization), and London dispersion energies, which are described using atom-dependent transferable parameters. As validated by comparison with high-level quantum mechanical energies, DFT-CES2 demonstrates chemical accuracy in describing interfacial interactions. DFT-CES2 enables the investigation of complex solid-liquid interfaces while avoiding extensive parametrization. Therefore, we expect DFT-CES2 to be broadly applicable for elucidating atom-scale details of large scale solid-liquid interfaces for multicomponent systems.