Step 6 Combining the Poisson and Maxwell-Boltzmann equations

8 Step 6 Combining the Poisson and Maxwell-Boltzmann equations 

The Maxwell-Boltzmann equation has been converted into the equation  

Substituting the equation for Pj (Equation 10.26) into the Poisson equation gives  

This equation is called the Poisson-Boltzmann equation and is in principle solvable to give an explicit expression for in terms of r. 

This then gives the contribution to the free energy due to non-ideality. 

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