I’m trying to reproduce some results from the PNAS paper titled ’ Energy decomposition analysis of single bonds within Kohn–Sham density functional theory’
Two part question:
1) As a start I have used example input 12.23 given in the Q-Chem 5.3 manual for the fluorine diatomic (changing the method and basis-set to wB97M-V/aug-cc-pVTZ as is specified in the PNAS paper).This job runs fine, however there is a significant difference in my results to the reported values, mainly coming from the spin-coupling, and charge-transfer terms, resulting in a difference in the total interaction energy of 10.4 kcal/mol:
Bonded-EDA (wB97M-V/aug-cc-pVTZ) - fluorine diatomic (All values in kcal/mol)
My results
E(Prep) = +9.2
E(FRZ) = +186.3
E(SC) = -129.6
E(POL) = -38.8
E(CT) = -77.6
E(Total) = -50.5
PNAS Results (Table 3)
E(Prep) = +9.2
E(FRZ) = +186.3
E(SC) = -124.1
E(POL) = -37.2
E(CT) = -74.3
E(Total) = -40.1
This difference is quite large. Am I missing something from the paper? No other details are provided in the methods section.
This brings me to my second question.
2) If I try to increase the SCF convergence threshold I get hung up on the SCF convergence for the charge-transfer term on the super system. The job fails - Segmentation fault - Error in the serial run.
This happens for almost every molecule I have tried. For those jobs that do finish successfully if I use the same input and simply change the molecule (replace F2 for Cl2) the job fails at the same SCF step for charge-transfer of the super-system. This mainly happens when is use basis sets of triple-zeta quality. Maybe I’m missing something but i cant understand why a job that finishes successfully for F2 would fail for Cl2.
This may be naive, but it seems to me that the bonded EDA is a lot less ‘black-box’ than the non-bonded ALMO-EDA model. What sort of things should i be looking-out for when preparing the input for these jobs? Any advice from the ALMO-EDA developers would help.
Thank You