Chemical-potentials-control.md

+# Ajusting of chemical potentials
+Static codes adjust chemical potentials automatically in such a way to provide a solution with requested particle number. Following parameters control adjusting process:
+```bash
+muchange                0.5      # coefficient for changing chemical potential, default=0.5
+mumaxchange             0.05     # maximal allowed changed of chemical potential per iteration,
+                                 # in units of Fermi energy
+```
+Chemical potentials are adjusted according to rule:  
+```math
+\begin{aligned}
+\Delta\mu_{\sigma}^{(i)} &= \textrm{muchange}\,\frac{N_{\sigma}^{(\textrm{req.})}-N_{\sigma}^{(i)}}{N_{\sigma}^{(\textrm{req.})}}\\
+\textrm{if}\,|\Delta\mu_{\sigma}^{(i)}/\varepsilon_F|&>\textrm{mumaxchange}:\,\textrm{decrease}\,\textrm{magnitude}\,\textrm{of}\,\Delta\mu_{\sigma}^{(i)}\\
+\mu_{\sigma}^{(i+1)} &= \mu_{\sigma}^{(i+1)} + \Delta\mu_{\sigma}^{(i)} 
+\end{aligned}
+```
+
+# Fixed chemical potential mode
+TODO
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