Hello, I have a doubt regarding WHICH type of energy does Avogadro calculate. Formation entalphy? I don’t think so because I compared it to bibliographic data and it’s not the same. From what experimental data does the program calculate the energy?
Best regards,
Blanca
It depends on which force field you’re using. By default, it will use the MMFF94 energy, which is intended to simulate a heat of formation, but of course it’s a classical force field, so it’s not terribly accurate.
Hope that helps!
Okay thank you. But if I want to compare it to bibliographic data to prove that is elegible for my Chemistry project, where can I find data that is similar to the Avogadro energy values with MMFF94 force field?
Thanks
Does Avogadro have the capability to calculate other energy values besides heat of formation? Like total energy or electronic energy?
Avogadro 1.2 has interfaces to a wide range of QM programs, including MOPAC, Gaussian, Orca, etc. (e.g., Extensions ⇒… pick your QM program of interest).
Avogadro 1.98 and later also have the same input generators to run calculations, but also have a new framework to enable calculations and optimizations with other programs (e.g., ML potentials like ANI-1x or GFN-FF / GFN-2, etc.)
My suggestion is to run a calculation. Orca, for example, is free for academic / personal use and B97-3c is a fast DFT method. (Actually, many methods will be fast on molecules this small.)
Another good package would be xtb which offers GFN-FF / GFN2 and is very fast.
Of course if you want heats of formation or \Delta G values, you’ll need to do a bit more work, but the results will be significantly more accurate than a force field.