I am interested in the formation energy. I've searched the mailing address, but I still can't get it. I found the definition of formation energy is like this (Ga15MnN16 for example) :formation energy = total ENE of Ga15MnN16 -15*total ENE for Ga metal in standard state structure - 1* total ENE for Mn metal in standard state structure - 16* total ENE for N in standard structure

`Correct. But more precisely: 'minus 15 * [total energy per atom] for Ga`

`metal" etc. Make sure that the number of atoms of each element at the`

`left and at the righ of the equation is identical. If not, the energy`

`differences will not make sense.`

In our system, it's TbOCl, does that mean: formation energy = = total ENE of TbOCl - tot ENE for Tb metal in standard state structure - tot ENE for O in standard state - Cl in standard state. ? If that is correct, what is the standard state structure for O and Cl? Do we need to do several other calculations for Tb metal or O standard state to get the formation energy?

`You do need to do additional calculations for all these reference`

`materials, indeed. In order to avoid having to perform the entire`

`structural optimization yourself, you can go here:`

http://dx.doi.org/10.1080/10408436.2013.772503

`Go to supplemental material. The file CIFs.tar.gz contains cif files`

`with the geometry of all the crystals you need. The lattice parameters`

`in these cif files are not necessarily exactly the optimized ones (with`

`PBE), but close to. If you start the optimization process from there`

`(with the functional that is relevant for you), you'll save some time.`

Stefaan _______________________________________________ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html