deletions | additions       diff --git a/2_Cuprates_Chuck_101_EPL__.tex b/2_Cuprates_Chuck_101_EPL__.tex  index eeb6356..2076927 100644  --- a/2_Cuprates_Chuck_101_EPL__.tex  +++ b/2_Cuprates_Chuck_101_EPL__.tex 
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Corrections to LDA/GGA energies for convex hull construction have been systematically investigated for transition metal oxides [PRB 73, 195107 (2006), PRB 84, 045115 (2011)]. The corrections arise from two sources: (a) the GGA overbinding of the anion (most commonly the $O_2$ molecule) and (b) correlations. The GGA overbinding differs based on the anion, and the corrections are tabulated in the Materials Project.  %  The correlation corrections are further divided into two components: (1) a contribution due to the U for atomic-like orbitals, treated by LDA+U, and (2) a correction in the energies required when comparing correlated (modeled using LDA+U) and uncorrelated (modeled using LDA) compounds. This is often the case in construction phase diagrams containing transition metal ions as their behavior can be considered “correlated” or “uncorrelated” depending on their valence and chemical environment. %  In earlier work, we had proposed several chemical reaction pathways to synthesize La2CuS2O2 and La2CuSO3 [PRB 89, 094517 (2014)] which were subsequently tested by experiment [ref. Hua He, unpublished] and concluded that the two compounds were unstable (at least at high temperatures). Additionally, LaCuSO seemed to be quite stable at high temperatures, as it was the preferred quaternary composition in almost all the experimentally analyzed reactions. %  With modern materials databases, we are able to reanalyze the entire La-Cu-S-O system to construct the convex hull (plotted in Fig. 1) and globally investigate stability. Notice that La2CuS2O2 and La2CuSO3 are not among the stable compounds on the hull. %  Using the convex hull, we can assess the stability of the reactants and products reported in experiment. In Fig. 2, we plot the energies relative to the convex hull for all reported compounds. Negative values are stability energies against decomposition. We find that La2CuS2O2 and La2CuSO3 are highly unstable at nearly 500meV/atom above the hull. Additionally, LaCuSO is marginally unstable at 23meV/atom above the hull, but this is indistinguishable from zero given the error bars of the current method. In hindsight, we could have predicted that the proposed compounds would not have formed and instead have decomposed into: %  La2CuS2O2 => La2SO2 + CuS 4 %4  La2CuSO3 => 3 La2SO2 + 4 Cu + La2SO6 We %We  also investigate the sensitivity of the stability energies to the LDA+U correction (denoted $\Delta E_M$ in Eq. 6 of PRB 84, 045115 (2011)). Varying  $\Delta E_M$ from 0.75eV/atom to 0.65eV/atom shifts the stability energies by  less than ~20meV/atom, well within LDA’s error bars, and our conclusions remain