diff --git a/pixi.lock b/pixi.lock
index 84d1225d90c5110da23e4e7f1cb2f5e0590945c9..9cac341b232a521cbad2d29dc5ec4bc34122a698 100644
--- a/pixi.lock
+++ b/pixi.lock
@@ -17,6 +17,7 @@ environments:
       - conda: https://conda.anaconda.org/conda-forge/linux-64/ca-certificates-2025.1.31-hbcca054_0.conda
       - conda: https://conda.anaconda.org/conda-forge/linux-64/cairo-1.18.4-h3394656_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/click-8.1.8-pyh707e725_0.conda
+      - conda: https://conda.anaconda.org/conda-forge/noarch/colorama-0.4.6-pyhd8ed1ab_1.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/comm-0.2.2-pyhd8ed1ab_1.conda
       - conda: https://conda.anaconda.org/conda-forge/linux-64/contourpy-1.3.1-py311hd18a35c_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/cycler-0.12.1-pyhd8ed1ab_1.conda
@@ -41,6 +42,7 @@ environments:
       - conda: https://conda.anaconda.org/conda-forge/linux-64/harfbuzz-11.0.1-h2c12942_0.conda
       - conda: https://conda.anaconda.org/conda-forge/linux-64/icu-75.1-he02047a_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/importlib-metadata-8.6.1-pyha770c72_0.conda
+      - conda: https://conda.anaconda.org/conda-forge/noarch/iniconfig-2.0.0-pyhd8ed1ab_1.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/ipykernel-6.29.5-pyh3099207_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/ipython-9.1.0-pyhfb0248b_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/ipython_pygments_lexers-1.1.1-pyhd8ed1ab_0.conda
@@ -126,6 +128,7 @@ environments:
       - conda: https://conda.anaconda.org/conda-forge/noarch/pip-25.0.1-pyh8b19718_0.conda
       - conda: https://conda.anaconda.org/conda-forge/linux-64/pixman-0.44.2-h29eaf8c_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/platformdirs-4.3.7-pyh29332c3_0.conda
+      - conda: https://conda.anaconda.org/conda-forge/noarch/pluggy-1.5.0-pyhd8ed1ab_1.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/prompt-toolkit-3.0.50-pyha770c72_0.conda
       - conda: https://conda.anaconda.org/conda-forge/linux-64/psutil-7.0.0-py311h9ecbd09_0.conda
       - conda: https://conda.anaconda.org/conda-forge/linux-64/pthread-stubs-0.4-hb9d3cd8_1002.conda
@@ -134,6 +137,7 @@ environments:
       - conda: https://conda.anaconda.org/conda-forge/noarch/pygments-2.19.1-pyhd8ed1ab_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/pyparsing-3.2.3-pyhd8ed1ab_1.conda
       - conda: https://conda.anaconda.org/conda-forge/linux-64/pyside6-6.9.0-py311h9053184_0.conda
+      - conda: https://conda.anaconda.org/conda-forge/noarch/pytest-8.3.5-pyhd8ed1ab_0.conda
       - conda: https://conda.anaconda.org/conda-forge/linux-64/python-3.11.11-h9e4cc4f_2_cpython.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/python-dateutil-2.9.0.post0-pyhff2d567_1.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/python-tzdata-2025.2-pyhd8ed1ab_0.conda
@@ -150,6 +154,7 @@ environments:
       - conda: https://conda.anaconda.org/conda-forge/noarch/stack_data-0.6.3-pyhd8ed1ab_1.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/threadpoolctl-3.6.0-pyhecae5ae_0.conda
       - conda: https://conda.anaconda.org/conda-forge/linux-64/tk-8.6.13-noxft_h4845f30_101.conda
+      - conda: https://conda.anaconda.org/conda-forge/noarch/tomli-2.2.1-pyhd8ed1ab_1.conda
       - conda: https://conda.anaconda.org/conda-forge/linux-64/tornado-6.4.2-py311h9ecbd09_0.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/traitlets-5.14.3-pyhd8ed1ab_1.conda
       - conda: https://conda.anaconda.org/conda-forge/noarch/typing_extensions-4.13.1-pyh29332c3_0.conda
@@ -326,6 +331,15 @@ packages:
   license_family: BSD
   size: 84705
   timestamp: 1734858922844
+- conda: https://conda.anaconda.org/conda-forge/noarch/colorama-0.4.6-pyhd8ed1ab_1.conda
+  sha256: ab29d57dc70786c1269633ba3dff20288b81664d3ff8d21af995742e2bb03287
+  md5: 962b9857ee8e7018c22f2776ffa0b2d7
+  depends:
+  - python >=3.9
+  license: BSD-3-Clause
+  license_family: BSD
+  size: 27011
+  timestamp: 1733218222191
 - conda: https://conda.anaconda.org/conda-forge/noarch/comm-0.2.2-pyhd8ed1ab_1.conda
   sha256: 7e87ef7c91574d9fac19faedaaee328a70f718c9b4ddadfdc0ba9ac021bd64af
   md5: 74673132601ec2b7fc592755605f4c1b
@@ -582,6 +596,15 @@ packages:
   license_family: APACHE
   size: 29141
   timestamp: 1737420302391
+- conda: https://conda.anaconda.org/conda-forge/noarch/iniconfig-2.0.0-pyhd8ed1ab_1.conda
+  sha256: 0ec8f4d02053cd03b0f3e63168316530949484f80e16f5e2fb199a1d117a89ca
+  md5: 6837f3eff7dcea42ecd714ce1ac2b108
+  depends:
+  - python >=3.9
+  license: MIT
+  license_family: MIT
+  size: 11474
+  timestamp: 1733223232820
 - conda: https://conda.anaconda.org/conda-forge/noarch/ipykernel-6.29.5-pyh3099207_0.conda
   sha256: 33cfd339bb4efac56edf93474b37ddc049e08b1b4930cf036c893cc1f5a1f32a
   md5: b40131ab6a36ac2c09b7c57d4d3fbf99
@@ -1583,6 +1606,15 @@ packages:
   license_family: MIT
   size: 23291
   timestamp: 1742485085457
+- conda: https://conda.anaconda.org/conda-forge/noarch/pluggy-1.5.0-pyhd8ed1ab_1.conda
+  sha256: 122433fc5318816b8c69283aaf267c73d87aa2d09ce39f64c9805c9a3b264819
+  md5: e9dcbce5f45f9ee500e728ae58b605b6
+  depends:
+  - python >=3.9
+  license: MIT
+  license_family: MIT
+  size: 23595
+  timestamp: 1733222855563
 - conda: https://conda.anaconda.org/conda-forge/noarch/prompt-toolkit-3.0.50-pyha770c72_0.conda
   sha256: 0749c49a349bf55b8539ce5addce559b77592165da622944a51c630e94d97889
   md5: 7d823138f550b14ecae927a5ff3286de
@@ -1673,6 +1705,23 @@ packages:
   license_family: LGPL
   size: 10104768
   timestamp: 1743760689943
+- conda: https://conda.anaconda.org/conda-forge/noarch/pytest-8.3.5-pyhd8ed1ab_0.conda
+  sha256: 963524de7340c56615583ba7b97a6beb20d5c56a59defb59724dc2a3105169c9
+  md5: c3c9316209dec74a705a36797970c6be
+  depends:
+  - colorama
+  - exceptiongroup >=1.0.0rc8
+  - iniconfig
+  - packaging
+  - pluggy <2,>=1.5
+  - python >=3.9
+  - tomli >=1
+  constrains:
+  - pytest-faulthandler >=2
+  license: MIT
+  license_family: MIT
+  size: 259816
+  timestamp: 1740946648058
 - conda: https://conda.anaconda.org/conda-forge/linux-64/python-3.11.11-h9e4cc4f_2_cpython.conda
   build_number: 2
   sha256: e0be7ad95a034d10e021f15317bf5c70fc1161564fa47844984c245505cde36c
@@ -1922,6 +1971,15 @@ packages:
   license_family: BSD
   size: 3318875
   timestamp: 1699202167581
+- conda: https://conda.anaconda.org/conda-forge/noarch/tomli-2.2.1-pyhd8ed1ab_1.conda
+  sha256: 18636339a79656962723077df9a56c0ac7b8a864329eb8f847ee3d38495b863e
+  md5: ac944244f1fed2eb49bae07193ae8215
+  depends:
+  - python >=3.9
+  license: MIT
+  license_family: MIT
+  size: 19167
+  timestamp: 1733256819729
 - conda: https://conda.anaconda.org/conda-forge/linux-64/tornado-6.4.2-py311h9ecbd09_0.conda
   sha256: afa3489113154b5cb0724b0bf120b62df91f426dabfe5d02f2ba09e90d346b28
   md5: df3aee9c3e44489257a840b8354e77b9
diff --git a/pixi.toml b/pixi.toml
index 011a0493fd7cd67bd9789ed449fb009bdc50990c..1eeb6364c5b1cb46e16563f8f9578e8710216f73 100644
--- a/pixi.toml
+++ b/pixi.toml
@@ -17,3 +17,4 @@ scikit-learn = ">=1.6.1,<2"
 black = ">=25.1.0,<26"
 pandas = ">=2.2.3,<3"
 biopython = ">=1.85,<2"
+pytest = ">=8.3.5,<9"
diff --git a/tests/test_bm_calc_residue_dist.py b/tests/test_bm_calc_residue_dist.py
index 2f478773e98ca69964fd6774b758d3365570792d..fd141b20d28c0e41261719d77a8cfeaf0af6e007 100644
--- a/tests/test_bm_calc_residue_dist.py
+++ b/tests/test_bm_calc_residue_dist.py
@@ -2,6 +2,7 @@ import Bio.PDB
 from Bio.PDB.Residue import Residue
 from Bio.PDB.Atom import Atom
 from pytest import MonkeyPatch, approx
+import numpy as np
 import pytest
 from unittest import TestCase
 from src.BioHelpers_FABER.bio_mod import calc_residue_dist
@@ -11,7 +12,7 @@ RESIDUES = list(STRUCTURE.get_residues())
 
 
 def test_null_vectors(monkeypatch: MonkeyPatch):
-    monkeypatch.setattr(Atom, "get_coord", lambda _: [0, 0, 0])
+    monkeypatch.setattr(Atom, "get_coord", lambda _: np.zeros(3))
     assert calc_residue_dist(RESIDUES[5], RESIDUES[5]) == 0.0
     assert (
         calc_residue_dist(RESIDUES[5], RESIDUES[5], res_type="rna", reference="nearest")
diff --git a/tests/test_bm_get_ref_coord.py b/tests/test_bm_get_ref_coord.py
index fc16f0862ea49d1f8f5dd1b8aac6e45f95004790..fea7ed60d8f27dbc2c1f51245d8e6b56daecab1e 100644
--- a/tests/test_bm_get_ref_coord.py
+++ b/tests/test_bm_get_ref_coord.py
@@ -25,7 +25,7 @@ def test_get_ref_coord_nitrogen():
 
 
 def test_get_ref_coord_nearest():
-    expected_val = np.array([0, 0, 0], dtype=np.float32)
+    expected_val = np.array([20.483, 18.827, 16.128], dtype=np.float32)
     np.testing.assert_equal(
         get_reference_coordinates(RESIDUES[5], RESIDUES[5], reference="nearest"),
         (