diff --git a/src/nos/data/helmholtz/domain_properties/file_input.py b/src/nos/data/helmholtz/domain_properties/file_input.py
index a9624d19..b57bfae1 100644
--- a/src/nos/data/helmholtz/domain_properties/file_input.py
+++ b/src/nos/data/helmholtz/domain_properties/file_input.py
@@ -139,6 +139,9 @@ def read_c_shaped_crystal(config: configparser.ConfigParser) -> List[CrystalDesc
     inner_radii = inner_radii.flatten()
     gap_widths = gap_widths.flatten()
 
+    inner_radii = outer_radii * inner_radii
+    gap_widths = inner_radii * gap_widths
+
     return [
         CShapeDescription(c.grid_size, c.n, outer, inner, gap)
         for outer, inner, gap in zip(outer_radii, inner_radii, gap_widths)
diff --git a/src/nos/data/helmholtz/mesh/crystal_builder.py b/src/nos/data/helmholtz/mesh/crystal_builder.py
index b9b9b1ca..a7f1bfa9 100644
--- a/src/nos/data/helmholtz/mesh/crystal_builder.py
+++ b/src/nos/data/helmholtz/mesh/crystal_builder.py
@@ -109,9 +109,9 @@ def define_tools(self) -> List[int]:
         tools = []
 
         # inner radius and gap in terms of the outer radius
-        inner_radius = self.crystal_description.radius * self.crystal_description.inner_radius
+        inner_radius = self.crystal_description.inner_radius
         # gaps should be smaller than inner radius
-        gap_height = min([inner_radius, self.crystal_description.gap_width * self.crystal_description.radius])
+        gap_height = self.crystal_description.gap_width
         tol = 1.1  # to prevent cutting artifacts
         gap_width = self.crystal_description.radius * tol