deletions | additions       diff --git a/XC Functionals.tex b/XC Functionals.tex  index 2ba1194..040f65f 100644  --- a/XC Functionals.tex  +++ b/XC Functionals.tex 
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Besides the functionals that are supported by Octopus, the code has  served as a platform for the testing and development of new  functionals. For example, the method described in section  \ref{sec:mbse} can be used in a straighforward straightforward  way to obtain reference data against which to benchmark the performance of a given xc  functional. In that case, both calculations, exact and approximate,  make use of the same real-space grid approach, which makes the  comparison of the results obtained with both straighforward. straightforward.  Despite the obvious advantage of using exact solutions of the many-body  problem as reference data, this is often not possible and one usually  needs to resort to the more commonly used experimental or