  Quantum embedding methods have become a powerful tool to overcome
deficiencies of traditional quantum modelling in materials science. However,
while these are systematically improvable in principle, in practice it is
rarely possible to achieve rigorous convergence and often necessary to employ
empirical parameters. Here, we formulate a quantum embedding theory, building
on the methods of density-matrix embedding theory combined with local
correlation approaches from quantum chemistry, to ensure the ability to
systematically converge properties of real materials with accurate correlated
wave~function methods, controlled by a single, rapidly convergent parameter. By
expanding supercell size, basis set, and the resolution of the fluctuation
space of an embedded fragment, we show that the systematic improvability of the
approach yields accurate structural and electronic properties of realistic
solids without empirical parameters, even across changes in geometry. Results
are presented in insulating, semi-metallic, and more strongly correlated
regimes, finding state of the art agreement to experimental data.
