Energy per atom of metal

[ams_nanolab]

How to calculate energy/atom of metals as Li or Na (bulk) ?

[Petr Khomyakov]

You can calculate the total energy using the analysis object 'Total energy' and divide it by the number of atoms to get the total energy per atom.

[ams_nanolab]

In the case of Na for example, I add the BCC Na structure from database (i.e. Na(beta)), use 16x16x16 k-points to simulate bulk and as the cell contains just one atom, that should be the total energy/atom (Em) of BCC Na?

Also how I get the cohesive energy of Na? Simulate a single na atom and subtract from previous energy/atom(Em)?

[Petr Khomyakov]

In the case of Na for example, I add the BCC Na structure from database (i.e. Na(beta)), use 16x16x16 k-points to simulate bulk and as the cell contains just one atom, that should be the total energy/atom (Em) of BCC Na?

Yes. Otherwise, the total energy of an ideal crystal is infinite because it is comprised of an infinite number of atoms.

Also how I get the cohesive energy of Na? Simulate a single na atom and subtract from previous energy/atom(Em)?

I guess so, see https://en.wiktionary.org/wiki/cohesive_energy.