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\subsection{Valence Disproportionation: TlCsCl3}  \label{sec:tlcscl3}  Potassium-doped barium bismuth oxide ($Ba_{1-x} K_x Bi O_3$), is a famous high temperature superconductor, discovered in the late 1980s~\cite{Sleight_1975, Cava_1988}. Its parent compound, BaBiO$_3$, has a distorted perovskite structure, with a band gap of $\sim 0.2$~eV~\cite{Sleight_1975}. Doping the material, with K for example, suppresses the structural distortions and makes the material superconducting, reaching with  a transition temperature of nearly 30~K at optimal doping. DFT does not describe the insulating character of the parent compound. Conventional Additionally,  DFT estimates of the electron phonon coupling $\lambda$ within Migdal-Eliasberg theory give a value of 0.34 in the doped compound, too small to account for its superconductivity~\cite{Meregalli_1998}. Examining the effect of correlations, we found that $\lambda$ is substantially enhanced relative to its DFT estimate to a value of nearly $1.0$, and that this enhancement is responsible for superconductivity in doped  BaBiO$_3$~\cite{Yin_2013}. We argue that correlations similarly enhance the electron phonon coupling in other materials proximate to an insulating state, accounting for superconductivity in systems such as HfNCl, borocarbides and buckminsterfullerenes. For these materials the most important type of correlation that needs to be treated is the static (in the solid state physicist convention) correlations. Hence a GW, or a hybrid DFT calculation is enough to correct the electronic structure of this material. After these calculations are done, one is left with a strongly coupled electron phonon system (after the static corrections to the Kohn Sham potential $\lambda ~ 1$). This coupling induces a large dynamical self energy, which accounts for the anomalous optical properties of this system~\cite{Nourafkan_2012} at relatively low energies ( less than 1 ev). Following M. Norman's cited above, we searched for other materials in that class. Materials whose parent compound would be strongly mixed valent and where the electron phonon coupling would be understimated by LDA, so that they would be candidates to be another " other high temperature superconductor". This example illustrates several aspects of the general discussion of the previous sections and contains several useful lessons.  \emph{Electronic structure}. In this material static correlations are very important, they thus require GW or hybrid DFT to make correct predictions (for example, the large electron phonon coupling and the tendency to valence disproportionation) and its a case that LDA is not a good guide to the electronic strucure. Identification strucure.Identification  of the level and the nature of the correlations is thus very important for a successful material design problem. The parent compound was succesfully synthesized, and the prediction realized, because it is likely that its total energy lied well below the the convex hull. The indications come from the energetics of a few reaction pathways were computed and they turned out to be hexothermic ( I THIN THIS IS NECESSARY BUT NOT SUFFICIENT CONDITION AND THAT ONE SHOULD DRAW COLOR MAPS INDICATING WHERE NEW COMPOUNDS LIE ). LIE).  \emph{Structural prediction} The Structural design proceeded by analogy with BaBiO$_3$ and the local stability was checked by computing phonon modes with LDA. However experiments revealed another allotropes. It would be interesting to see if these would show up in more general searches with algorithms such as genetic algorithms or xxxx mentioned in section yyy.  \emph{Structural prediction} \emph{Global stability}  The Structural design proceeded by analogy with BaBiO$_3$ parent compound was succesfully synthesized,  and the local stability was checked by computing   phonon modes with LDA. However experiments revealed another allotropes. It would be interesting prediction realized, because it is likely that its total energy lied well below the the convex hull. The indications come from the energetics of a few reaction pathways were computed and they turned out  to see if these would show up in more general  searches with algorithms such as genetic algorithms or xxxx mentioned in section yyy. be hexothermic ( I THIN THIS IS NECESSARY BUT NOT SUFFICIENT CONDITION AND THAT ONE SHOULD DRAW COLOR MAPS INDICATING WHERE NEW COMPOUNDS LIE ).  \emph{Global stability} The parent compound was succesfully synthesized, and the prediction realized, because it is likely that its total energy lied  well below the the convex hull. The indications come from the energetics of a few reaction pathways were computed and they turned out to be hexothermic ( I THIN THIS IS NECESSARY BUT NOT SUFFICIENT CONDITION AND THAT ONE SHOULD DRAW COLOR MAPS INDICATING WHERE NEW COMPOUNDS LIE ). Attempts to dope this material were carried out but were unsuccessful. The full solid state solution replacing Tl by Hg for example was studied in ref \cite{Retuerto_2013} however the material remains insulating. This deserves more careful investitation to see if it is the result of phonon induced self localization or disorder.