16.4 fitting the energy levels

We minimise the \(\chi^2\) \[ \chi^2= \sum_i \frac{( \Delta E_2^{predicted} -\Delta E_2^{latt})^2}{\sigma^2} \]

\[\begin{gather} \chi^2/d.o.f.=0.654318 \\ P[0]=-0.152424\pm (0.0016) \\ P[1]=-2.79804\pm (0.2) \\ \end{gather}\] {\[\begin{gather} C=\begin{pmatrix} 1& 0.00107\\ 0.00107& 1\\ \end{pmatrix} \end{gather}\]}