EOS plot data and formatting needs work

[edan-bainglass]

From @giovannipizzi

There is a problem with the REF for oxygen for XO and X2O5. I’m quite sure it’s a factor of 2 in the volume - for those 2 systems, the AE use a smaller cell. One should use the information on how many atoms there are in the unit cell from the corresponding JSON file, and normalize by that (i.e. not hardcode the division by 2).

[edan-bainglass]

@giovannipizzi indeed, the values were half w.r.t (the average of) the rest. @unkcpz can you have a look at the data? I believe I took this from here. Not sure if there is updated data somewhere.

[edan-bainglass]

For now, I manually doubled the above two, which fixes it for oxygen. Best if @unkcpz revisits the original data and its generating script (for all elements).