2.4.5.2 Nernst Coefficients

The isothermal Nernst coefficients $\eta_n$ ($\eta_p$) characterize the transverse gradient of the quasi Fermi potential caused by the deflection of an electron (hole) heat current flowing 'down a temperature gradient':

$$\eta_{n,p} = - \frac{\nabla\phi_{n,p}\cdot (\mathbf{B}\times\nabla T_{n,p})} {(\mathbf{B}\times\nabla T_{n,p})^2} \quad \mathbf{J_{n,p}}=0$$ (2.12)