chore: fix tests_on_pr

Author: ycexiao

tests/helper.py

@@ -261,7 +261,7 @@ def run_nanoparticle_example():
 
 
 def run_c60_example():
-    global_namespace = {"c60xyz_path": str(_DATA_DIR / "C60xyz.txt")}
+    global_namespace = {"c60xyz_path": str(_DATA_DIR / "c60xyz.txt")}
     local_namespace = {}
     exec(
         (Path(__file__).parent / "data" / "make_c60.txt").read_text(),