diff --git a/.github/actions/setup_lfs/action.yml b/.github/actions/setup_lfs/action.yml
index b3c76be7977..86a3b0464d4 100644
--- a/.github/actions/setup_lfs/action.yml
+++ b/.github/actions/setup_lfs/action.yml
@@ -3,10 +3,6 @@ description: "Pull LFS repositories and caches them"
 
 
 inputs:
-  refdata-repo:
-    description: "tardis refdata repository"
-    required: false
-    default: "tardis-sn/tardis-refdata"
   regression-data-repo:
     description: "tardis regression data repository"
     required: false
@@ -15,47 +11,6 @@ inputs:
 runs:
   using: "composite"
   steps:
-    - name: Clone Refdata Repo
-      uses: actions/checkout@v4
-      with:
-        repository: ${{ inputs.refdata-repo }}
-        path: tardis-refdata
-        lfs: false
-
-    - name: Create LFS file list
-      run: git lfs ls-files -l | cut -d' ' -f1 | sort > .lfs-assets-id
-      working-directory: tardis-refdata
-      shell: bash
-
-    - name: Restore LFS cache
-      uses: actions/cache/restore@v4
-      id: lfs-cache-refdata
-      with:
-        path: tardis-refdata/.git/lfs
-        key: ${{ runner.os }}-lfs-${{ hashFiles('tardis-refdata/.lfs-assets-id') }}-v1
-
-    - name: Git LFS Pull
-      run: git lfs pull
-      working-directory: tardis-refdata
-      if: steps.lfs-cache-refdata.outputs.cache-hit != 'true'
-      shell: bash
-
-    - name: Git LFS Checkout
-      run: git lfs checkout
-      working-directory: tardis-refdata
-      if: steps.lfs-cache-refdata.outputs.cache-hit == 'true'
-      shell: bash
-
-    - name: Save LFS cache if not found
-      # uses fake ternary
-      # for reference: https://github.com/orgs/community/discussions/26738#discussioncomment-3253176
-      if: ${{ steps.lfs-cache-refdata.outputs.cache-hit != 'true' && !contains(github.ref, 'merge') && always() || false }}
-      uses: actions/cache/save@v4
-      id: lfs-cache-refdata-save
-      with:
-        path: tardis-refdata/.git/lfs
-        key: ${{ runner.os }}-lfs-${{ hashFiles('tardis-refdata/.lfs-assets-id') }}-v1
-
     - name: Clone tardis-sn/tardis-regression-data
       uses: actions/checkout@v4
       with:
diff --git a/.github/workflows/dispatcher.yml b/.github/workflows/archive/dispatcher.yml
similarity index 100%
rename from .github/workflows/dispatcher.yml
rename to .github/workflows/archive/dispatcher.yml
diff --git a/.github/workflows/build-docs.yml b/.github/workflows/build-docs.yml
index 254c19ffbdd..a630187331b 100644
--- a/.github/workflows/build-docs.yml
+++ b/.github/workflows/build-docs.yml
@@ -92,15 +92,15 @@ jobs:
 
       - name: Setup LFS
         uses: ./.github/actions/setup_lfs
-      
+
       - name: Setup environment
         uses: ./.github/actions/setup_env
-        with: 
+        with:
           os-label: linux-64
 
       - name: Copy atom_data
         run: |
-          mkdir -p ~/Downloads/tardis-data && cp -a ./tardis-refdata/atom_data/. ~/Downloads/tardis-data
+          mkdir -p ~/Downloads/tardis-data && cp -a ./tardis-regression-data/atom_data/. ~/Downloads/tardis-data
 
       - name: Install package
         run: pip install -e .
diff --git a/.github/workflows/pre-release.yml b/.github/workflows/pre-release.yml
index 78b159e8b95..6dc7a8b8ace 100644
--- a/.github/workflows/pre-release.yml
+++ b/.github/workflows/pre-release.yml
@@ -30,14 +30,14 @@ jobs:
       - name: Download Lock File
         run:  wget -q https://raw.githubusercontent.com/tardis-sn/tardis/master/conda-linux-64.lock
         shell: bash
-        
+
       - name: Generate Cache Key
-        run: | 
+        run: |
           file_hash=$(cat conda-linux-64.lock | shasum -a 256 | cut -d' ' -f1)
           echo "file_hash=$file_hash" >> "${GITHUB_OUTPUT}"
         id: cache-environment-key
         shell: bash
-          
+
       - uses: mamba-org/setup-micromamba@v1
         with:
           environment-file: conda-linux-64.lock
@@ -95,7 +95,7 @@ jobs:
 
             <br>
 
-            > :warning: **WARNING:** 
+            > :warning: **WARNING:**
             >
             > This pull request should be auto-merged. **Do not merge manually if any check fails**.
             >
@@ -138,9 +138,6 @@ jobs:
           merge-method: squash
         if: steps.create-pr.outputs.pull-request-operation == 'created'
 
-  compare_refdata:
-    uses: tardis-sn/tardis-refdata/.github/workflows/compare-refdata.yml@master
-  
   pip_tests:
     uses: ./.github/workflows/tests.yml
     secrets: inherit
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 2213398c1bd..281071a0472 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -16,7 +16,7 @@ on:
       - reopened
       - synchronize
       - labeled
-  workflow_call: # to be called by the pre release workflow
+  workflow_call:
     inputs:
       pip_git:
         description: "Whether or not to install tardis using git"
@@ -25,8 +25,8 @@ on:
         default: false
 
 env:
-  CACHE_NUMBER: 0 # increase to reset cache manually
-  PYTEST_FLAGS: --tardis-refdata=${{ github.workspace }}/tardis-refdata --tardis-regression-data=${{ github.workspace }}/tardis-regression-data --cov=tardis --cov-report=xml --cov-report=html --cov-append
+  CACHE_NUMBER: 0  # increase to reset cache manually
+  PYTEST_FLAGS: --tardis-regression-data=${{ github.workspace }}/tardis-regression-data --cov=tardis --cov-report=xml --cov-report=html --cov-append
   CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
 
 defaults:
@@ -88,7 +88,7 @@ jobs:
       - name: Run tests
         run: pytest tardis ${{ env.PYTEST_FLAGS }} -m "${{ matrix.continuum }} continuum and ${{ matrix.rpacket_tracking }} rpacket_tracking"
 
-      - name: Refdata Generation tests
+      - name: Regression Data Generation tests
         run: pytest tardis ${{ env.PYTEST_FLAGS }} --generate-reference -m "${{ matrix.continuum }} continuum and ${{ matrix.rpacket_tracking }} rpacket_tracking"
         if: contains(github.event.pull_request.labels.*.name, 'run-generation-tests') || github.ref == 'refs/heads/master'
 
@@ -97,6 +97,7 @@ jobs:
       - uses: actions/upload-artifact@v4
         with:
           name: coverage-${{ matrix.continuum }}-continuum-${{ matrix.rpacket_tracking }}-rpacket_tracking-${{ matrix.os }}
+          include-hidden-files: true
           path: |
             .coverage*
             !.coveragerc
diff --git a/asv.conf.json b/asv.conf.json
index 3fe4f4ec10f..f0157be649c 100644
--- a/asv.conf.json
+++ b/asv.conf.json
@@ -26,7 +26,7 @@
     "html_dir": ".asv/html",
     "matrix": {
         "env": {
-            "TARDIS_REF_PATH": "tardis-refdata/atom_data"
+            "TARDIS_REF_PATH": "tardis-regression-data/atom_data"
         }
     }
 }
\ No newline at end of file
diff --git a/docs/io/configuration/components/models/data/config_init_trad.yml b/docs/io/configuration/components/models/data/config_init_trad.yml
index cb4ecb5c1a7..f8de5dc8149 100755
--- a/docs/io/configuration/components/models/data/config_init_trad.yml
+++ b/docs/io/configuration/components/models/data/config_init_trad.yml
@@ -9,7 +9,7 @@ supernova:
   time_explosion: 16 day
   distance: 8.32 Mpc
 
-# standard atomic data base; get it from the tardis-refdata repository
+# standard atomic data base; get it from the tardis-regression-data repository
 atom_data: kurucz_cd23_chianti_H_He.h5
 
 model:
diff --git a/docs/io/configuration/components/models/data/config_no_init_trad.yml b/docs/io/configuration/components/models/data/config_no_init_trad.yml
index 1b1f2c1aad1..33fe99b3ab1 100755
--- a/docs/io/configuration/components/models/data/config_no_init_trad.yml
+++ b/docs/io/configuration/components/models/data/config_no_init_trad.yml
@@ -9,7 +9,7 @@ supernova:
   time_explosion: 16 day
   distance: 8.32 Mpc
 
-# standard atomic data base; get it from the tardis-refdata repository
+# standard atomic data base; get it from the tardis-regression-data repository
 atom_data: kurucz_cd23_chianti_H_He.h5
 
 model:
diff --git a/docs/resources/code_comparison/plasma_compare/tardis_example.yml b/docs/resources/code_comparison/plasma_compare/tardis_example.yml
index 1cf7cab151d..d23c8e741a2 100644
--- a/docs/resources/code_comparison/plasma_compare/tardis_example.yml
+++ b/docs/resources/code_comparison/plasma_compare/tardis_example.yml
@@ -6,7 +6,7 @@ supernova:
   time_explosion: 13 day
   #distance: 24.2 Mpc
 
-# standard atomic data base; get it from the tardis-refdata repository
+# standard atomic data base; get it from the tardis-regression-data repository
 atom_data: kurucz_cd23_chianti_H_He.h5
 
 model:
diff --git a/tardis/conftest.py b/tardis/conftest.py
index 8d5f6ad78b7..e38c7eafa51 100644
--- a/tardis/conftest.py
+++ b/tardis/conftest.py
@@ -1,4 +1,5 @@
 import os
+from copy import deepcopy
 from pathlib import Path
 
 import pytest
@@ -91,9 +92,6 @@ def pytest_configure(config):
 
 
 def pytest_addoption(parser):
-    parser.addoption(
-        "--tardis-refdata", default=None, help="Path to Tardis Reference Folder"
-    )
     parser.addoption(
         "--tardis-regression-data",
         default=None,
@@ -141,17 +139,20 @@ def generate_reference(request):
     option = request.config.getoption("--generate-reference")
     if option is None:
         return False
-    else:
-        return option
+    return option
 
 
 @pytest.fixture(scope="session")
-def tardis_ref_path(request):
-    tardis_ref_path = request.config.getoption("--tardis-refdata")
-    if tardis_ref_path is None:
-        pytest.skip("--tardis-refdata was not specified")
+def tardis_regression_path(request):
+    tardis_regression_path = request.config.getoption(
+        "--tardis-regression-data"
+    )
+    if tardis_regression_path is None:
+        pytest.skip("--tardis-regression-data was not specified")
     else:
-        return Path(os.path.expandvars(os.path.expanduser(tardis_ref_path)))
+        return Path(
+            os.path.expandvars(os.path.expanduser(tardis_regression_path))
+        )
 
 
 @pytest.fixture(scope="session")
diff --git a/tardis/energy_input/docs/working_gamma_ray_test.ipynb b/tardis/energy_input/docs/working_gamma_ray_test.ipynb
index e952944ed1d..77188813146 100644
--- a/tardis/energy_input/docs/working_gamma_ray_test.ipynb
+++ b/tardis/energy_input/docs/working_gamma_ray_test.ipynb
@@ -89,7 +89,7 @@
     }
    ],
    "source": [
-    "# Download the atom data file from tardis-refdata repo to run this cell.\n",
+    "# Download the atom data file from tardis-regression-data repo to run this cell.\n",
     "atom_data_file = 'kurucz_cd23_chianti_H_He.h5'\n",
     "atom_data = AtomData.from_hdf(atom_data_file)"
    ]
diff --git a/tardis/io/model/parse_atom_data.py b/tardis/io/model/parse_atom_data.py
index 66b95fb4ffe..86665af0e4a 100644
--- a/tardis/io/model/parse_atom_data.py
+++ b/tardis/io/model/parse_atom_data.py
@@ -45,7 +45,7 @@ def parse_atom_data(config, atom_data=None):
             print(
                 e,
                 "Error might be from the use of an old-format of the atomic database, \n"
-                "please see https://github.com/tardis-sn/tardis-refdata/tree/master/atom_data"
+                "please see https://github.com/tardis-sn/tardis-regression-data/tree/master/atom_data"
                 " for the most recent version.",
             )
             raise
diff --git a/tardis/io/model/readers/tests/data/csvy_test_config.yml b/tardis/io/model/readers/tests/data/csvy_test_config.yml
index 3df6d499810..c22e9a40b91 100644
--- a/tardis/io/model/readers/tests/data/csvy_test_config.yml
+++ b/tardis/io/model/readers/tests/data/csvy_test_config.yml
@@ -5,7 +5,7 @@ supernova:
   luminosity_requested: 8.770 log_lsun
   time_explosion: 16 day
 
-# standard atomic data base; get it from the tardis-refdata repository
+# standard atomic data base; get it from the tardis-regression-data repository
 atom_data: kurucz_cd23_chianti_H_He.h5
 
 csvy_model: csvy_full.csvy
diff --git a/tardis/io/model/readers/tests/test_arepo_parser.py b/tardis/io/model/readers/tests/test_arepo_parser.py
index d205d9d90ed..7d831f3df3f 100644
--- a/tardis/io/model/readers/tests/test_arepo_parser.py
+++ b/tardis/io/model/readers/tests/test_arepo_parser.py
@@ -7,8 +7,8 @@
 
 
 @pytest.fixture()
-def arepo_snapshot_fname(tardis_ref_path):
-    return Path(tardis_ref_path) / "arepo_data" / "arepo_snapshot.json"
+def arepo_snapshot_fname(tardis_regression_path):
+    return Path(tardis_regression_path) / "arepo_data" / "arepo_snapshot.json"
 
 
 @pytest.fixture
diff --git a/tardis/model/tests/data/branch85_csvy.yml b/tardis/model/tests/data/branch85_csvy.yml
index 336d76344e3..f1f4628caf0 100644
--- a/tardis/model/tests/data/branch85_csvy.yml
+++ b/tardis/model/tests/data/branch85_csvy.yml
@@ -6,7 +6,7 @@ supernova:
   time_explosion: 16 day
   distance: 8.32 Mpc
 
-# standard atomic data base; get it from the tardis-refdata repository
+# standard atomic data base; get it from the tardis-regression-data repository
 atom_data: kurucz_cd23_chianti_H_He.h5
 
 csvy_model: branch85_csvy.csvy
diff --git a/tardis/model/tests/data/branch85_old_config.yml b/tardis/model/tests/data/branch85_old_config.yml
index 1056660e91a..de1d41159fc 100644
--- a/tardis/model/tests/data/branch85_old_config.yml
+++ b/tardis/model/tests/data/branch85_old_config.yml
@@ -6,7 +6,7 @@ supernova:
   time_explosion: 16 day
   distance: 8.32 Mpc
 
-# standard atomic data base; get it from the tardis-refdata repository
+# standard atomic data base; get it from the tardis-regression-data repository
 atom_data: kurucz_cd23_chianti_H_He.h5
 
 
diff --git a/tardis/model/tests/data/csvy_model_to_test_abundances.yml b/tardis/model/tests/data/csvy_model_to_test_abundances.yml
index 28828109bfd..d4f1722d75d 100644
--- a/tardis/model/tests/data/csvy_model_to_test_abundances.yml
+++ b/tardis/model/tests/data/csvy_model_to_test_abundances.yml
@@ -6,7 +6,7 @@ supernova:
   time_explosion: 4 day
   distance: 8.32 Mpc
 
-# standard atomic data base; get it from the tardis-refdata repository
+# standard atomic data base; get it from the tardis-regression-data repository
 atom_data: kurucz_cd23_chianti_H_He.h5
 
 csvy_model: csvy_model_to_test_abundances.csvy
diff --git a/tardis/model/tests/data/exponential_csvy.yml b/tardis/model/tests/data/exponential_csvy.yml
index 0712767be5f..96f170e9e9c 100644
--- a/tardis/model/tests/data/exponential_csvy.yml
+++ b/tardis/model/tests/data/exponential_csvy.yml
@@ -6,7 +6,7 @@ supernova:
   time_explosion: 16 day
   distance: 8.32 Mpc
 
-# standard atomic data base; get it from the tardis-refdata repository
+# standard atomic data base; get it from the tardis-regression-data repository
 atom_data: kurucz_cd23_chianti_H_He.h5
 
 csvy_model: exponential_csvy.csvy
diff --git a/tardis/model/tests/data/exponential_old_config.yml b/tardis/model/tests/data/exponential_old_config.yml
index 64bba2d1124..026bd218e69 100644
--- a/tardis/model/tests/data/exponential_old_config.yml
+++ b/tardis/model/tests/data/exponential_old_config.yml
@@ -6,7 +6,7 @@ supernova:
   time_explosion: 16 day
   distance: 8.32 Mpc
 
-# standard atomic data base; get it from the tardis-refdata repository
+# standard atomic data base; get it from the tardis-regression-data repository
 atom_data: kurucz_cd23_chianti_H_He.h5
 
 
diff --git a/tardis/model/tests/data/model_full_csvy.yml b/tardis/model/tests/data/model_full_csvy.yml
index 642356c95e2..47a6d29beb5 100644
--- a/tardis/model/tests/data/model_full_csvy.yml
+++ b/tardis/model/tests/data/model_full_csvy.yml
@@ -6,7 +6,7 @@ supernova:
   time_explosion: 16 day
   distance: 8.32 Mpc
 
-# standard atomic data base; get it from the tardis-refdata repository
+# standard atomic data base; get it from the tardis-regression-data repository
 atom_data: kurucz_cd23_chianti_H_He.h5
 
 csvy_model: model_full_csvy.csvy
diff --git a/tardis/model/tests/data/model_full_old_config.yml b/tardis/model/tests/data/model_full_old_config.yml
index a88ea398c97..925017a76ce 100644
--- a/tardis/model/tests/data/model_full_old_config.yml
+++ b/tardis/model/tests/data/model_full_old_config.yml
@@ -6,7 +6,7 @@ supernova:
   time_explosion: 16 day
   distance: 8.32 Mpc
 
-# standard atomic data base; get it from the tardis-refdata repository
+# standard atomic data base; get it from the tardis-regression-data repository
 atom_data: kurucz_cd23_chianti_H_He.h5
 
 
diff --git a/tardis/model/tests/data/powerlaw_csvy.yml b/tardis/model/tests/data/powerlaw_csvy.yml
index aa28f208a1a..a4af6bb592a 100644
--- a/tardis/model/tests/data/powerlaw_csvy.yml
+++ b/tardis/model/tests/data/powerlaw_csvy.yml
@@ -6,7 +6,7 @@ supernova:
   time_explosion: 16 day
   distance: 8.32 Mpc
 
-# standard atomic data base; get it from the tardis-refdata repository
+# standard atomic data base; get it from the tardis-regression-data repository
 atom_data: kurucz_cd23_chianti_H_He.h5
 
 csvy_model: powerlaw_csvy.csvy
diff --git a/tardis/model/tests/data/powerlaw_old_config.yml b/tardis/model/tests/data/powerlaw_old_config.yml
index 8713c040040..5099d54f118 100644
--- a/tardis/model/tests/data/powerlaw_old_config.yml
+++ b/tardis/model/tests/data/powerlaw_old_config.yml
@@ -6,7 +6,7 @@ supernova:
   time_explosion: 16 day
   distance: 8.32 Mpc
 
-# standard atomic data base; get it from the tardis-refdata repository
+# standard atomic data base; get it from the tardis-regression-data repository
 atom_data: kurucz_cd23_chianti_H_He.h5
 
 
diff --git a/tardis/model/tests/data/radiative_csvy.yml b/tardis/model/tests/data/radiative_csvy.yml
index b3f33d3eea7..388cad75db3 100644
--- a/tardis/model/tests/data/radiative_csvy.yml
+++ b/tardis/model/tests/data/radiative_csvy.yml
@@ -5,7 +5,7 @@ supernova:
   time_explosion: 16 day
   distance: 8.32 Mpc
 
-# standard atomic data base; get it from the tardis-refdata repository
+# standard atomic data base; get it from the tardis-regression-data repository
 atom_data: kurucz_cd23_chianti_H_He.h5
 
 csvy_model: radiative_csvy.csvy
diff --git a/tardis/model/tests/data/radiative_old_config.yml b/tardis/model/tests/data/radiative_old_config.yml
index 97be58b892c..e476e7346ce 100644
--- a/tardis/model/tests/data/radiative_old_config.yml
+++ b/tardis/model/tests/data/radiative_old_config.yml
@@ -6,7 +6,7 @@ supernova:
   time_explosion: 16 day
   distance: 8.32 Mpc
 
-# standard atomic data base; get it from the tardis-refdata repository
+# standard atomic data base; get it from the tardis-regression-data repository
 atom_data: kurucz_cd23_chianti_H_He.h5
 
 
diff --git a/tardis/model/tests/data/uniform_csvy.yml b/tardis/model/tests/data/uniform_csvy.yml
index faa09f0ae1b..693595a4fe6 100644
--- a/tardis/model/tests/data/uniform_csvy.yml
+++ b/tardis/model/tests/data/uniform_csvy.yml
@@ -6,7 +6,7 @@ supernova:
   time_explosion: 16 day
   distance: 8.32 Mpc
 
-# standard atomic data base; get it from the tardis-refdata repository
+# standard atomic data base; get it from the tardis-regression-data repository
 atom_data: kurucz_cd23_chianti_H_He.h5
 
 csvy_model: uniform_csvy.csvy
diff --git a/tardis/model/tests/data/uniform_old_config.yml b/tardis/model/tests/data/uniform_old_config.yml
index 9f494eaa96e..5273286c732 100644
--- a/tardis/model/tests/data/uniform_old_config.yml
+++ b/tardis/model/tests/data/uniform_old_config.yml
@@ -6,7 +6,7 @@ supernova:
   time_explosion: 16 day
   distance: 8.32 Mpc
 
-# standard atomic data base; get it from the tardis-refdata repository
+# standard atomic data base; get it from the tardis-regression-data repository
 atom_data: kurucz_cd23_chianti_H_He.h5
 
 
diff --git a/tardis/plasma/tests/data/config_init_trad.yml b/tardis/plasma/tests/data/config_init_trad.yml
index a7ecefcd289..a48ff352f26 100755
--- a/tardis/plasma/tests/data/config_init_trad.yml
+++ b/tardis/plasma/tests/data/config_init_trad.yml
@@ -9,7 +9,7 @@ supernova:
   time_explosion: 16 day
   distance: 8.32 Mpc
 
-# standard atomic data base; get it from the tardis-refdata repository
+# standard atomic data base; get it from the tardis-regression-data repository
 atom_data: kurucz_cd23_chianti_H_He.h5
 
 model:
diff --git a/tardis/plasma/tests/test_complete_plasmas.py b/tardis/plasma/tests/test_complete_plasmas.py
index 60f9ae85abc..579dfaa52fb 100644
--- a/tardis/plasma/tests/test_complete_plasmas.py
+++ b/tardis/plasma/tests/test_complete_plasmas.py
@@ -136,8 +136,10 @@ class TestPlasma:
     scalars_properties = ["time_explosion", "link_t_rad_t_electron"]
 
     @pytest.fixture(scope="class")
-    def chianti_he_db_fpath(self, tardis_ref_path):
-        return (tardis_ref_path / "atom_data" / "chianti_He.h5").absolute()
+    def chianti_he_db_fpath(self, tardis_regression_path):
+        return (
+            tardis_regression_path / "atom_data" / "chianti_He.h5"
+        ).absolute()
 
     @pytest.fixture(scope="class", params=CONFIG_LIST, ids=idfn)
     def config(self, request):
diff --git a/tardis/spectrum/tests/__init__.py b/tardis/spectrum/tests/__init__.py
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/tardis/tests/fixtures/atom_data.py b/tardis/tests/fixtures/atom_data.py
index d2b4c7b084a..8cecbc44ffa 100644
--- a/tardis/tests/fixtures/atom_data.py
+++ b/tardis/tests/fixtures/atom_data.py
@@ -10,9 +10,9 @@
 
 
 @pytest.fixture(scope="session")
-def atomic_data_fname(tardis_ref_path):
+def atomic_data_fname(tardis_regression_path):
     atomic_data_fname = (
-        tardis_ref_path / "atom_data" / "kurucz_cd23_chianti_H_He.h5"
+        tardis_regression_path / "atom_data" / "kurucz_cd23_chianti_H_He.h5"
     )
 
     atom_data_missing_str = (
@@ -44,11 +44,16 @@ def kurucz_atomic_data(atomic_dataset):
 
 
 @pytest.fixture  # (scope="session")
-def nlte_atomic_data_fname(tardis_ref_path):
+def nlte_atomic_data_fname(tardis_regression_path):
     """
     File name for the atomic data file used in NTLE ionization solver tests.
     """
-    atomic_data_fname = tardis_ref_path / "nlte_atom_data" / "TestNLTE_He_Ti.h5"
+    atomic_data_fname = (
+        tardis_regression_path
+        / "atom_data"
+        / "nlte_atom_data"
+        / "TestNLTE_He_Ti.h5"
+    )
 
     atom_data_missing_str = (
         f"{atomic_data_fname} atomic datafiles " f"does not seem to exist"