Design Decisions in the Creation of Parameter Free Embedding Theories

The development of parameter-free Quantum Embedding methods for the simulation of real materials requires design decisions ranging from the choice of spatial basis functions to the choice of quantum impurity solver. This general overview talk will highlight some of the design decisions behind popular choices and their associated costs and benefits; illustrate the presence of `hidden' free parameters where they exist, and motivate the need for future algorithmic development needed to advance the field. A route towards systematically improvable parameter-free adaptive simulations of quantum materials is outlined.