[Pw_forum] heat of formation for Mg3N2

[Xiangmei Duan]

Dear Stefano,

I found the problem about the heat of formation for Mg3N2, which came from 
the bulk Mg. The binding energy I got 4.95/2 eV is too large comparing to 
other LDA calc. (~1.76-1.78 eV) and expt. vealus (1.51 eV).
My lattice parameter c is too large !!! - not fully optimized !

Now the binding energy for Mg bulk is 1.79 eV, and the heat of formation 
for Mg3N2 is -4.97 eV.

Sorry for my carelessness,
Best wishes,
Xiangmei