where 𝑆 𝑂 2 𝑇,𝑝 0 is the entropy of the O2 molecule taken from the JANAF thermochemical tables , 𝑝 𝑂 2 is the partial pressure of O2 gas and 𝑝 0 is the partial pressure of oxygen in the standard state. Structure figures were produced using the VESTA software package .