We can also assume the lattice parameter of the cubic unit cell to be a and the that of the extended cell to be a', which means that V' = (a')^3
So is the number of atoms n' in the extended volume V' equal to:
n' = n x (V'/V) ?
The basis of this question arises from the fact that I have the Energy of a system in a terms of eV/atom. And I want to calculate the total electronic energy of the extended volume.
We can assume the unit cell to be conventional for the ease of calculation.