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)