diff --git a/src/qmllib/representations/fchl/fchl_electric_field_kernels.py b/src/qmllib/representations/fchl/fchl_electric_field_kernels.py
index a3abba47..c1a19260 100644
--- a/src/qmllib/representations/fchl/fchl_electric_field_kernels.py
+++ b/src/qmllib/representations/fchl/fchl_electric_field_kernels.py
@@ -1,6 +1,7 @@
 from __future__ import absolute_import
 
 import numpy as np
+
 from qmllib.utils.alchemy import get_alchemy
 
 from .fchl_kernel_functions import get_kernel_parameters
diff --git a/src/qmllib/representations/fchl/fchl_force_kernels.py b/src/qmllib/representations/fchl/fchl_force_kernels.py
index 3e276b35..e921abfc 100644
--- a/src/qmllib/representations/fchl/fchl_force_kernels.py
+++ b/src/qmllib/representations/fchl/fchl_force_kernels.py
@@ -1,6 +1,7 @@
 from __future__ import absolute_import
 
 import numpy as np
+
 from qmllib.utils.alchemy import get_alchemy
 
 from .fchl_kernel_functions import get_kernel_parameters
diff --git a/src/qmllib/representations/fchl/fchl_representations.py b/src/qmllib/representations/fchl/fchl_representations.py
index 168b487c..2e3ddf1c 100644
--- a/src/qmllib/representations/fchl/fchl_representations.py
+++ b/src/qmllib/representations/fchl/fchl_representations.py
@@ -3,6 +3,7 @@
 import copy
 
 import numpy as np
+
 from qmllib.utils import ELEMENT_NAME
 
 
diff --git a/src/qmllib/representations/fchl/fchl_scalar_kernels.py b/src/qmllib/representations/fchl/fchl_scalar_kernels.py
index 9ae0b1d4..f438d467 100644
--- a/src/qmllib/representations/fchl/fchl_scalar_kernels.py
+++ b/src/qmllib/representations/fchl/fchl_scalar_kernels.py
@@ -1,6 +1,7 @@
 from __future__ import absolute_import
 
 import numpy as np
+
 from qmllib.utils.alchemy import get_alchemy
 
 from .fchl_kernel_functions import get_kernel_parameters
diff --git a/tests/test_acsf.py b/tests/test_acsf.py
index 03d16ee8..c8904d6b 100644
--- a/tests/test_acsf.py
+++ b/tests/test_acsf.py
@@ -7,6 +7,7 @@
 
 import numpy as np
 import tensorflow as tf
+
 from qmllib.aglaia import np_symm_funct, symm_funct
 
 
diff --git a/tests/test_arad.py b/tests/test_arad.py
index b3abb9ad..3bb595e3 100644
--- a/tests/test_arad.py
+++ b/tests/test_arad.py
@@ -3,6 +3,8 @@
 import os
 
 import numpy as np
+
+import qmllib
 from qmllib.arad import (
     generate_arad_representation,
     get_atomic_kernels_arad,
@@ -13,8 +15,6 @@
     get_local_symmetric_kernels_arad,
 )
 
-import qmllib
-
 
 def get_energies(filename):
     """Returns a dictionary with heats of formation for each xyz-file."""
diff --git a/tests/test_armp.py b/tests/test_armp.py
index 06e25631..4a37f887 100644
--- a/tests/test_armp.py
+++ b/tests/test_armp.py
@@ -8,6 +8,7 @@
 import shutil
 
 import numpy as np
+
 from qmllib.aglaia.aglaia import ARMP
 from qmllib.utils import InputError
 
diff --git a/tests/test_fchl_electric_field.py b/tests/test_fchl_electric_field.py
index 95975f06..f661ab9a 100644
--- a/tests/test_fchl_electric_field.py
+++ b/tests/test_fchl_electric_field.py
@@ -6,6 +6,8 @@
 from copy import deepcopy
 
 import numpy as np
+from scipy.linalg import lstsq
+
 from qmllib.fchl import (
     generate_displaced_representations,
     generate_representation,
@@ -15,8 +17,6 @@
     get_atomic_local_kernels,
     get_gaussian_process_electric_field_kernels,
 )
-from scipy.linalg import lstsq
-
 from qmllib.math import cho_solve
 
 DEBYE_TO_EAA = 0.20819434
diff --git a/tests/test_fchl_force.py b/tests/test_fchl_force.py
index cbcb7d20..e553318b 100644
--- a/tests/test_fchl_force.py
+++ b/tests/test_fchl_force.py
@@ -8,6 +8,8 @@
 import numpy as np
 import scipy
 import scipy.stats
+from scipy.linalg import lstsq
+
 from qmllib.fchl import (
     generate_displaced_representations,
     generate_displaced_representations_5point,
@@ -23,8 +25,6 @@
     get_local_symmetric_hessian_kernels,
     get_local_symmetric_kernels,
 )
-from scipy.linalg import lstsq
-
 from qmllib.math import cho_solve
 
 test_dir = os.path.dirname(os.path.realpath(__file__))
diff --git a/tests/test_fchl_scalar.py b/tests/test_fchl_scalar.py
index 7cf0b2c4..0d705066 100644
--- a/tests/test_fchl_scalar.py
+++ b/tests/test_fchl_scalar.py
@@ -3,6 +3,9 @@
 import os
 
 import numpy as np
+from scipy.special import binom, factorial, jn
+
+from qmllib import Compound
 from qmllib.fchl import (
     generate_representation,
     get_atomic_kernels,
@@ -12,9 +15,6 @@
     get_local_kernels,
     get_local_symmetric_kernels,
 )
-from scipy.special import binom, factorial, jn
-
-from qmllib import Compound
 from qmllib.math import cho_solve
 
 
diff --git a/tests/test_mrmp.py b/tests/test_mrmp.py
index 70d8a42c..554a6935 100644
--- a/tests/test_mrmp.py
+++ b/tests/test_mrmp.py
@@ -7,6 +7,7 @@
 import shutil
 
 import numpy as np
+
 from qmllib.aglaia.aglaia import MRMP
 from qmllib.utils import InputError
 
diff --git a/tests/test_symm_funct.py b/tests/test_symm_funct.py
index e9496186..2f1188ba 100644
--- a/tests/test_symm_funct.py
+++ b/tests/test_symm_funct.py
@@ -7,9 +7,9 @@
 
 import numpy as np
 import tensorflow as tf
-from qmllib.aglaia import symm_funct
 
 import qmllib
+from qmllib.aglaia import symm_funct
 from qmllib.representations import generate_acsf