Clarification about Frost diagram y-axis conventions? I was looking at the Frost diagram of Manganese, and on the UC Davis ChemWiki, I see this one:



However, the one straight from my textbook, "Descriptive Inorganic Chemistry" (Overton), looks like this:



In the first image, the y-axis is $\mathbf{nE^o}$ and the x-axis goes from 0 to +7 from left to right, but in the second image, the y-axis is $\mathbf{-nE^o}$ and the x-axis goes from +7 to 0 from left to right.

I'm wondering if reversing the oxidation state ordering changes the y-axis definition between $nE^o$ and $-nE^o$. 

It seems like a silly question to me, but I still want to be sure.
The UC Davis version is incorrect. The free energy of the system ($\Delta G$) is equal to -nFE, so y-axis is reported as $\Delta G / F$ or -nE, according to the original report by Arthur Frost (J. Am. Chem. Soc., 1951, 73 (6), 2680-2682). 

Note: In the original report free energy was denoted by $\Delta F$, rather than $\Delta G$. The x-axis designation is insignificant.