diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 000000000..a61e5e3b9
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "carsus/io/tests/carsus-data-cmfgen"]
+	path = carsus/io/tests/carsus-data-cmfgen
+	url = https://github.com/tardis-sn/carsus-data-cmfgen
diff --git a/carsus/io/tests/carsus-data-cmfgen b/carsus/io/tests/carsus-data-cmfgen
new file mode 160000
index 000000000..001be3e43
--- /dev/null
+++ b/carsus/io/tests/carsus-data-cmfgen
@@ -0,0 +1 @@
+Subproject commit 001be3e43282ad4dcdd14cc6f2e9534ade5bf643
diff --git a/carsus/io/tests/test_cmfgen.py b/carsus/io/tests/test_cmfgen.py
index 0f9867e42..c9ff589fc 100644
--- a/carsus/io/tests/test_cmfgen.py
+++ b/carsus/io/tests/test_cmfgen.py
@@ -25,7 +25,7 @@
 def si1_reader():
     return CMFGENReader.from_config(
         "Si 0-1",
-        atomic_path="/tmp/atomic",
+        atomic_path="tmp/atomic",
         collisions=True,
         cross_sections=True,
         ionization_energies=True,
@@ -169,15 +169,27 @@ def test_get_seaton_phixs_table(threshold_energy_ryd, fit_coeff_list):
 
 
 @pytest.mark.array_compare
-@pytest.mark.parametrize("hyd_gaunt_energy_grid_ryd", [{1: list(range(1, 3))}])
+@pytest.mark.parametrize("hyd_gaunt_energy_grid_ryd", [{1: list(range(1, 4))}])
 @pytest.mark.parametrize("hyd_gaunt_factor", [{1: list(range(3, 6))}])
 @pytest.mark.parametrize("threshold_energy_ryd", [0.5])
 @pytest.mark.parametrize("n", [1])
+@pytest.mark.parametrize("hyd_n_phixs_stop2start_energy_ratio", [25])
+@pytest.mark.parametrize("hyd_n_phixs_num_points", [200])
 def test_get_hydrogenic_n_phixs_table(
-    hyd_gaunt_energy_grid_ryd, hyd_gaunt_factor, threshold_energy_ryd, n
+    hyd_gaunt_energy_grid_ryd,
+    hyd_gaunt_factor,
+    threshold_energy_ryd,
+    n,
+    hyd_n_phixs_stop2start_energy_ratio,
+    hyd_n_phixs_num_points,
 ):
     hydrogenic_n_phixs_table = get_hydrogenic_n_phixs_table(
-        hyd_gaunt_energy_grid_ryd, hyd_gaunt_factor, threshold_energy_ryd, n
+        hyd_gaunt_energy_grid_ryd,
+        hyd_gaunt_factor,
+        threshold_energy_ryd,
+        n,
+        hyd_n_phixs_stop2start_energy_ratio,
+        hyd_n_phixs_num_points,
     )
     return hydrogenic_n_phixs_table