Fixes #7162

Code/GraphMol/CMakeLists.txt

@@ -192,3 +192,6 @@ rdkit_catch_test(molbundleTestsCatch catch_molbundle.cpp
 
 rdkit_catch_test(pickleTestsCatch catch_pickles.cpp
         LINK_LIBRARIES FileParsers SmilesParse GraphMol)
+
+rdkit_catch_test(tableTestsCatch catch_periodictable.cpp
+        LINK_LIBRARIES GraphMol)

Code/GraphMol/atomic_data.cpp

@@ -132,10 +132,15 @@ const std::string periodicTableAtomData =
 82	Pb	1.46	1.48	2.3	207.2	4	208	207.9766521	2	4
 83	Bi	1.48	1.45	2.3	208.98	5	209	208.9803987	3	5	7
 84	Po	1.40	1.46	2.0	209	6	209	208.9824304	2	4	6
-85	At	1.50	1.45	2.0	210	7	210	209.987148	1	3	5
-86	Rn	1.50	2.4	2.0	222	8	211	210.990601	0
+85	At	1.50	1.45	2.0	210	7	210	209.987148	1	3	5)DAT"
+    // the values for Ra and Rn are from:
+    // https://www.ciaaw.org/atomic-masses.htm
+    // their most common isotopes are from
+    // https://www.ciaaw.org/radioactive-elements.htm
+    R"DAT(
+86	Rn	1.50	2.4	2.0	222	8	222 222.0175706 0
 87	Fr	2.6	2	2.0	223	1	223	223.0197359	1
-88	Ra	2.2	1.9	2.0	226	2	223	223.0185022	2	-1
+88	Ra	2.2	1.9	2.0	226	2	226 226.0254026	2	-1
 89	Ac	2.15	1.88	2.0	227	3	227	227.0277521	-1
 90	Th	2.06	1.79	2.4	232.038	4	232	232.0380553	-1
 91	Pa	2.00	1.61	2.0	231.036	3	231	231.035884	-1

Code/GraphMol/catch_periodictable.cpp

@@ -0,0 +1,29 @@
+//
+//  Copyright (C) 2024 Greg Landrum and other RDKit contributors
+//
+//   @@ All Rights Reserved @@
+//  This file is part of the RDKit.
+//  The contents are covered by the terms of the BSD license
+//  which is included in the file license.txt, found at the root
+//  of the RDKit source tree.
+//
+
+#include <catch2/catch_all.hpp>
+
+#include <GraphMol/RDKitBase.h>
+
+using namespace RDKit;
+
+TEST_CASE(
+    "Github #7162: Unexpected exact mass values are returned for radium and radon") {
+  SECTION("radium") {
+    CHECK(PeriodicTable::getTable()->getMostCommonIsotope(88) == 226);
+    CHECK(PeriodicTable::getTable()->getMassForIsotope(88, 226) ==
+          Catch::Approx(226.02540).epsilon(1e-4));
+  }
+  SECTION("radon") {
+    CHECK(PeriodicTable::getTable()->getMostCommonIsotope(86) == 222);
+    CHECK(PeriodicTable::getTable()->getMassForIsotope(86, 222) ==
+          Catch::Approx(222.01757).epsilon(1e-4));
+  }
+}