I got the cohesive energy by Pymatgen (get_cohesive_energy) using the Materials Project and found that most values of Nitrogen compounds are negative while those of other compounds are positive. According to the definition, the cohesive energy should be positive values. I wonder that the reference energy of N atom is wrong. Please check it. Thank you.
I’m looking into it right now. Do you have an example mpid with N-compounds with a negative cohesive energy and another with positive?
The mpid with N-compounds with negative cohesive energy such as:mp-1102,mp-1410,mp-883,mp-1975.And other compounds with positive cohesive energy ,such as:mp-33526,mp-1222395.
Some of the references were using the total energy of diatomic molecules rather than the isolated atom. This problem should be fixed now. I’ve checked the cohesive energies for the mpids you sent me, they should all be positive values.