I am having a hard time finding the constants and conversions that Avogadro uses. For example, when I open an .fchk file from Gaussian in Avogadro, HOMO LUMO energies are listed in eV. In the output file from Gaussian they are listed in Hartree. Sometimes when I convert the values myself using 1 Hartree = 27.2114 eV I get a difference in the third decimal place. I am hoping to know the exact equation Avogadro is using for this conversion and others.