deletions | additions       diff --git a/Schroedinger equation.tex b/Schroedinger equation.tex  index 43dfbde..528c082 100644  --- a/Schroedinger equation.tex  +++ b/Schroedinger equation.tex 
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\label{eq:SENd}  \hat{H}\Psi_j(x_1...x_N)=E_j\Psi_j(x_1...x_N)  \end{equation}  which provides a spatial wave function for a single electron in $N$ dimensions. This equivalence is not restricted to one-dimensional problems. One can generally map a problem of $N$ electrons in $d$ dimensions onto the problem of a single particle in $Nd$ dimensions, or indeed a problem with multiple types of particles in $d$ dimensions, in the same way. What we exploit here is the basic machinery for solving the Sch\"odinger equation iteratively, the spatial/grid bookkeeping, and the intrinsic parallelization of octopus. In order to keep our notation relatively simple, we will continue to discuss the case of an originally one-dimensional problem with $N$ electrons. The keywords associated to the following functionality are prefixed ``ModelMB'' for Model Many Body Schr\"odinger equations.  Solving Eq.\ (\ref{eq:SENd}) leaves the problem of constructing a wave function which satisfies the antisymmetry properties of $N$ electrons in one dimension. In particular, one needs to ensure that those spatial wave functions $\Psi_j$ which are not the spatial part of a properly antisymmetric wave function are removed as allowed solutions for the $N$-electron problem. A graphical representation of which wave functions are allowed are the classical Young diagrams for permutation symmetries, where each electron is asigned a box, and those boxes are then arranged in columns and rows. Each box is labeled with a number from 1 to $N$ such that the numbers increase from top to bottom and left to right.   %% NB: this is basic quantum mechanics, possibly not the place to add it here. I recommend we chop it out and add a reference to some QM textbook, even if we feel that it is not simple or well explained anywhere. A summary of the operation and the output of octopus would be sufficient.