code: def get_site_energy(self, site_index):
          
          if self._charged:
              warn('Per atom energies for charged structures not supported in EwaldSummation')
          return np.sum(self._recip[:,site_index]) + np.sum(self._real[:,site_index]) \
              + self._point[site_index]
docs: Compute the energy for a single site in the structure
          
          Args:
              site_index (int): Index of site
          ReturnS:
              (float) - Energy of that site