minor update, following update of global README

HeisenbergED/README.md

@@ -1,4 +1,4 @@
-**HeisenbergED** is an exact diagonalization implementation for the spin-1/2 XXX model, focusing on Sz- and momentum- sectors selection as a physics informed routine for the block-reduction of the eigenproblem. Due to prohibitive scaling of the many-body Hilbert space special attention has been devoted to memory management and fast build of matrices, following closely the standard reference by Sandvik ([arXiv:1101.3281](https://arxiv.org/abs/1101.3281)). Furthermore a statistical analysis based on *Phys. Rev. B 75, 155111 (2007)* has been carried out on the ED results. Correspondent preparatory lectures have been given by prof. Mario Collura at SISSA.
+**HeisenbergED** is an exact diagonalization implementation for the spin-1/2 XXX model, focusing on Sz- and momentum- sectors selection as a physics informed routine for the block-reduction of the eigenproblem. Due to prohibitive scaling of the many-body Hilbert space, special attention has been devoted to memory management and fast build of matrices, following closely the standard reference by Sandvik ([arXiv:1101.3281](https://arxiv.org/abs/1101.3281)). Further statistical analysis, based on *Phys. Rev. B 75, 155111 (2007)*, has been carried out on the ED results. Correspondent preparatory lectures have been given by prof. Mario Collura at SISSA.
 
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