To assess whether this convergence is also observed for PBE0, calculations were performed on a subset of the oxalic acid predicted crystal structures (Fig. and). We started from 20 crystal structures in 7 space groups. However, three of the PBE0/PW single point calculation did not converge in 48 hours on 192 computing cores and were abandoned. For the remaining 17 structures, errors in relative lattice energies with the smaller def2-SVP basis set are too large (MAE = 4.45 and MAX = 9.83 kJ mol -1 ), considering the close energetic spacing of predicted structures, with an R 2 of 0.490 to the PBE0/PW relatice lattice energies. The results using the larger def2-TZVP basis set have much better correlation to PW (R 2 = 0.926) while MAE and MAX errors are 1.37 and 3.41 kJ mol -1 , respectively. Given the much lower computational cost of PBE0/def2-TZVP than PW basis sets, we used this GTO basis set for PBE0 calculations of the energies for the full CSP structure sets for all three molecular systems (oxalic acid, urazole and maleic hydrazide).