Efficiently computing excitations of complex systems

Quantum embedding schemes have the potential to significantly reduce the computational cost of first-principles calculations while maintaining accuracy, particularly for calculations of electronic excitations in complex systems.

In this work by Dr Joseph C. A. Prentice, he combines time-dependent embedded mean field theory (TD-EMFT) with linear-scaling density functional theory and implicit solvation models, extending previous work within the ONETEP code.  This provides a way to perform multilevel calculations of electronic excitations on very large systems, where long-range environmental effects, both quantum and classical in nature, are important.

Dr Prentice demonstrates in his paper 'Efficiently computing excitations of complex systems: Linear-scaling time-dependent embedded mean-field theory in implicit solvent' (published in Journal of Chemical Theory and Computation) the power of this method by performing simulations on a variety of systems, including a molecular dimer, a chromophore in solution, and a doped molecular crystal.  

This work paves the way for high-accuracy calculations to be performed on large-scale systems that were previously beyond the reach of quantum embedding schemes.