def test4():
swnt = SWNT((10, 5))
assert_equal(swnt.element1, 'C')
assert_equal(swnt.element2, 'C')
print(swnt)
print(swnt.basis)
print(swnt.unit_cell)
print(type(swnt.basis))
print(swnt)
print(swnt.basis)
print(swnt.basis[:2])
print(type(swnt.basis[:2]))
print(swnt.crystal_cell)
print(swnt.crystal_cell.basis)
swnt.element1 = 'N'
assert_equal(swnt.element1, 'N')
print(swnt)
swnt.element2 = 'Ar'
assert_equal(swnt.element2, 'Ar')
print(swnt)
assert_equal(swnt.unit_cell.basis.symbols.tolist()[:2], ['N', 'Ar'])
assert_equal(swnt.crystal_cell.basis.symbols.tolist()[:2], ['N', 'Ar'])
assert_equal(swnt.basis, ['N', 'Ar'])
def test6():
swnt = SWNT((10, 5), element1='B', element2='N')
assert_equal(swnt.element1, 'B')
assert_equal(swnt.element2, 'N')
print(swnt)
print(swnt.unit_cell)
swnt.element1 = 'N'
swnt.element2 = 'B'
assert_equal(swnt.element1, 'N')
assert_equal(swnt.element2, 'B')
print(swnt)
print(swnt.unit_cell)
assert_equal(swnt.unit_cell.basis.symbols.tolist()[:2], ['N', 'B'])
assert_equal(swnt.crystal_cell.basis.symbols.tolist()[:2], ['N', 'B'])
assert_equal(swnt.basis, ['N', 'B'])
