a = 4.0
  d = 1.1
  from ASE import ListOfAtoms
  s1 = ListOfAtoms([])
  from ASE import Atom
  s1.append(Atom('C', (0.5,       0.5, 0.5)))
  s1.append(Atom('O', (0.5 + d/a, 0.5, 0.5)))
  s1.SetUnitCell([(a, 0, 0), (0, a, 0), (0, 0, a)])
  from Dacapo import Dacapo
  c1 = Dacapo()
  c1.SetNumberOfBands(10)
  s1.SetCalculator(c1) 
  c1.WriteAsNetCDFFile('data.nc')

e1 = s1.GetPotentialEnergy() 
print 'E = ', e1, '[eV]' 

a = 4.0
d = 1.1
#
a1 = (a, 0, 0)
a2 = (0, a, 0)
a3 = (0, 0, a)
#
v1 = (0.5, 0.5, 0.5) 
v2 = (0.5 + d/a, 0.5, 0.5)
#
from ASE import Atom
p1 = Atom('C', v1)
p2 = Atom('O', v2)
#
from ASE import ListOfAtoms
s1 = ListOfAtoms([p1, p2])
s1.SetUnitCell([a1, a2, a3])
#
from Dacapo import Dacapo
c1 = Dacapo()
c1.SetNumberOfBands(10)
s1.SetCalculator(c1) 
#
e1 = s1.GetPotentialEnergy() 
print 'E = ', e1, '[eV]'