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docs/6_bonds_and_spectra.md

@@ -645,7 +645,9 @@ You may assume that the masses and spring constants are equivalent throughout th
         In Python use the function [`numpy.diag`](https://docs.scipy.org/doc/numpy/reference/generated/numpy.diag.html).
 
 2. Using numerical diagonalization ([`numpy.linalg.eigvalsh`](https://docs.scipy.org/doc/numpy/reference/generated/numpy.linalg.eigvalsh.html)), compute the eigenfrequencies of this atomic chain. Plot a histogram of these eigenfrequencies.
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 3. Make the mass of every even atom different from the mass of every odd atom. Compute the eigenfrequencies of this atomic chain and plot a histogram.
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 4. Now make the masses of even and odd atoms equivalent again. Furthermore, make the spring constants of every even spring different from the odd spring.
 Compute the eigenfrequencies of this atomic chain and plot a histogram.