deletions | additions       diff --git a/correlations.tex b/correlations.tex  index 8432d0a..575ad3f 100644  --- a/correlations.tex  +++ b/correlations.tex 
...
\section{What are correlated materials?}  \label{sec:correlations}  Correlated The basic feature of correlated  materials are compounds where is their electrons cannot be described as non-interacting particles. Since  the behavior of its the  constituent electrons are strongly, rather than weakly, correlated strongly coupled  to one another. As a result of these strong interactions, another,  studying the behavior of individual particles generally provides little insight into the macroscopic properties of a correlated material. While this conceptual definition is valuable for understanding the fundamental physics, it is of less use to a DFT practitioner, who seeks to make predictions for comparison with experimental observations. To arrive at an operational definition of a correlated material, we examine DFT and how it relates to the observed electronic spectra. %% DFT is a workhorse of the materials science community, providing efficient and accurate computations of the total energy and distribution of electrons of a compound, requiring only the coordinates of the atoms in its crystal lattice as input. From the total energy, one can obtain lattice constants, equations of state and the spectrum of lattice vibrations. Furthermore, one can obtain electronic properties such as band gaps, electric polarization and topological numbers, which are by no means trivial for these "simple" compounds.