From eaed4009873e6dc28e0aa0794209be2857552163 Mon Sep 17 00:00:00 2001
From: GuySten <62616591+GuySten@users.noreply.github.com>
Date: Wed, 3 Sep 2025 05:52:27 +0200
Subject: [PATCH] Fixed a bug in plotting cross sections with S(a,b) data
 (#3558)

---
 openmc/plotter.py | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/openmc/plotter.py b/openmc/plotter.py
index 85c4963a76..693cdaca4e 100644
--- a/openmc/plotter.py
+++ b/openmc/plotter.py
@@ -413,7 +413,8 @@ def _calculate_cexs_nuclide(this, types, temperature=294., sab_name=None,
 
         # Prep S(a,b) data if needed
         if sab_name:
-            sab = openmc.data.ThermalScattering.from_hdf5(sab_name)
+            sab = openmc.data.ThermalScattering.from_hdf5(
+                library.get_by_material(sab_name, data_type='thermal')['path'])
             # Obtain the nearest temperature
             if strT in sab.temperatures:
                 sabT = strT
@@ -640,14 +641,13 @@ def _calculate_cexs_elem_mat(this, types, temperature=294.,
             sab = openmc.data.ThermalScattering.from_hdf5(
                 library.get_by_material(sab_name, data_type='thermal')['path'])
             for nuc in sab.nuclides:
-                sabs[nuc] = library.get_by_material(sab_name,
-                        data_type='thermal')['path']
+                sabs[nuc] = sab_name
     else:
         if sab_name:
-            sab = openmc.data.ThermalScattering.from_hdf5(sab_name)
+            sab = openmc.data.ThermalScattering.from_hdf5(
+                library.get_by_material(sab_name, data_type='thermal')['path'])
             for nuc in sab.nuclides:
-                sabs[nuc] = library.get_by_material(sab_name,
-                        data_type='thermal')['path']
+                sabs[nuc] = sab_name
 
     # Now we can create the data sets to be plotted
     xs = {}
@@ -655,8 +655,8 @@ def _calculate_cexs_elem_mat(this, types, temperature=294.,
     for nuclide in nuclides.items():
         name = nuclide[0]
         nuc = nuclide[1]
-        sab_tab = sabs[name]
-        temp_E, temp_xs = calculate_cexs(nuc, types, T, sab_tab, cross_sections,
+        sab_name = sabs[name]
+        temp_E, temp_xs = calculate_cexs(nuc, types, T, sab_name, cross_sections,
                                          ncrystal_cfg=ncrystal_cfg
                                          )
         E.append(temp_E)