diff --git a/jaxpm/distributed.py b/jaxpm/distributed.py
index 4fdb764..dbbb8fd 100644
--- a/jaxpm/distributed.py
+++ b/jaxpm/distributed.py
@@ -40,7 +40,7 @@ def ifft3d(x):
 def get_halo_size(halo_size, sharding):
     gpu_mesh = sharding.mesh if sharding is not None else None
     if gpu_mesh is None or gpu_mesh.empty:
-        zero_ext = (0, 0, 0)
+        zero_ext = (0, 0)
         zero_tuple = (0, 0)
         return (zero_tuple, zero_tuple, zero_tuple), zero_ext
     else:
diff --git a/jaxpm/painting.py b/jaxpm/painting.py
index 838fe38..fd52106 100644
--- a/jaxpm/painting.py
+++ b/jaxpm/painting.py
@@ -5,8 +5,8 @@ import jax.lax as lax
 import jax.numpy as jnp
 from jax.sharding import PartitionSpec as P
 
-from jaxpm.distributed import (autoshmap, get_halo_size, halo_exchange,
-                               slice_pad, slice_unpad, fft3d, ifft3d)
+from jaxpm.distributed import (autoshmap, fft3d, get_halo_size, halo_exchange,
+                               ifft3d, slice_pad, slice_unpad)
 from jaxpm.kernels import cic_compensation, fftk
 from jaxpm.painting_utils import gather, scatter
 
diff --git a/notebooks/03-MultiHost_PM.py b/notebooks/03-MultiHost_PM.py
index 06dccb7..9cda78b 100644
--- a/notebooks/03-MultiHost_PM.py
+++ b/notebooks/03-MultiHost_PM.py
@@ -7,21 +7,21 @@ jax.distributed.initialize()
 rank = jax.process_index()
 size = jax.process_count()
 
+from functools import partial
+
 import jax.numpy as jnp
 import jax_cosmo as jc
-
-from jaxpm.kernels import interpolate_power_spectrum
-from jaxpm.painting import cic_paint_dx
-from jaxpm.pm import linear_field, lpt, make_ode_fn
-
+import numpy as np
+from diffrax import (ConstantStepSize, LeapfrogMidpoint, ODETerm, SaveAt,
+                     diffeqsolve)
 from jax.experimental.mesh_utils import create_device_mesh
 from jax.experimental.multihost_utils import process_allgather
 from jax.sharding import Mesh, NamedSharding
 from jax.sharding import PartitionSpec as P
-from functools import partial
-import numpy as np
 
-from diffrax import ConstantStepSize, LeapfrogMidpoint, ODETerm, SaveAt, diffeqsolve
+from jaxpm.kernels import interpolate_power_spectrum
+from jaxpm.painting import cic_paint_dx
+from jaxpm.pm import linear_field, lpt, make_ode_fn
 
 all_gather = partial(process_allgather, tiled=True)
 
@@ -84,7 +84,8 @@ def run_simulation(omega_c, sigma8):
     return initial_conditions, dx, res.ys, res.stats
 
 
-initial_conditions , lpt_displacements , ode_solutions , solver_stats = run_simulation(0.25, 0.8)
+initial_conditions, lpt_displacements, ode_solutions, solver_stats = run_simulation(
+    0.25, 0.8)
 print(f"[{rank}] Simulation completed")
 print(f"[{rank}] Solver stats: {solver_stats}")
 
@@ -95,10 +96,9 @@ ode_solutions = [all_gather(sol) for sol in ode_solutions]
 
 if rank == 0:
     np.savez("multihost_pm.npz",
-                initial_conditions=initial_conditions,
-                lpt_displacements=lpt_displacements,
-                ode_solutions=ode_solutions,
-                solver_stats=solver_stats)
+             initial_conditions=initial_conditions,
+             lpt_displacements=lpt_displacements,
+             ode_solutions=ode_solutions,
+             solver_stats=solver_stats)
 
 print(f"[{rank}] Simulation results saved")
-    
\ No newline at end of file
diff --git a/notebooks/visualize.py b/notebooks/visualize.py
index 0db2273..0a3884b 100644
--- a/notebooks/visualize.py
+++ b/notebooks/visualize.py
@@ -1,6 +1,7 @@
-import numpy as np
 import jax.numpy as jnp
 import matplotlib.pyplot as plt
+import numpy as np
+
 
 def plot_fields(fields_dict, sum_over=None):
     """
@@ -23,8 +24,10 @@ def plot_fields(fields_dict, sum_over=None):
         slicing = tuple(slicing)
 
         # Sum projection over the specified axis and plot
-        axes[row, proj_axis].imshow(field[slicing].sum(axis=proj_axis) + 1, 
-                                    cmap='magma', extent=[0, field.shape[proj_axis], 0, field.shape[proj_axis]])
+        axes[row, proj_axis].imshow(
+            field[slicing].sum(axis=proj_axis) + 1,
+            cmap='magma',
+            extent=[0, field.shape[proj_axis], 0, field.shape[proj_axis]])
         axes[row, proj_axis].set_xlabel('Mpc/h')
         axes[row, proj_axis].set_ylabel('Mpc/h')
         axes[row, proj_axis].set_title(title)
@@ -32,7 +35,8 @@ def plot_fields(fields_dict, sum_over=None):
     # Plot each field across the three axes
     for i, (name, field) in enumerate(fields_dict.items()):
         for proj_axis in range(3):
-            plot_subplots(proj_axis, field, i, f"{name} projection {proj_axis}")
+            plot_subplots(proj_axis, field, i,
+                          f"{name} projection {proj_axis}")
 
     plt.tight_layout()
     plt.show()
diff --git a/setup.py b/setup.py
index 43b7315..b9b6b29 100644
--- a/setup.py
+++ b/setup.py
@@ -7,5 +7,5 @@ setup(
     author='JaxPM developers',
     description='A dead simple FastPM implementation in JAX',
     packages=find_packages(),
-    install_requires=['jax', 'jax_cosmo','jaxdecomp'],
+    install_requires=['jax', 'jax_cosmo', 'jaxdecomp'],
 )