def testCopy(self):
crystal = SiAlpha
atoms = crystal.atoms()
atoms.cell *= 1.5
store = atoms.copy()
crystal = TestRelaxationSystem(crystal, atoms)
new_crystal = crystal.copy()
self.assertIsInstance(new_crystal, DiamondStructure)
self.assertEqual(new_crystal.symbol(), 'Si')
atoms = new_crystal.atoms()
self.assertArraysEqual(store.cell, atoms.cell, 5)
