diff --git a/tests/opatIO/meson.build b/tests/opatIO/meson.build
index 8722176..bf7f1c3 100644
--- a/tests/opatIO/meson.build
+++ b/tests/opatIO/meson.build
@@ -13,7 +13,7 @@ foreach test_file : test_sources
   test_exe = executable(
       exe_name,
       test_file,
-      dependencies: [gtest_dep],
+      dependencies: [gtest_dep, picosha2_dep],
       include_directories: include_directories('../../src/opatIO/public'),
       link_with: libopatIO,  # Link the dobj library
       install_rpath: '@loader_path/../../src'  # Ensure runtime library path resolves correctly
diff --git a/tests/opatIO/opatIOTest.cpp b/tests/opatIO/opatIOTest.cpp
index 9b51e27..f950e86 100644
--- a/tests/opatIO/opatIOTest.cpp
+++ b/tests/opatIO/opatIOTest.cpp
@@ -5,8 +5,10 @@
 #include <vector>
 #include <set>
 #include <sstream>
+#include <cstring>
+#include "picosha2.h"
 
-std::string EXAMPLE_FILENAME = std::string(getenv("MESON_SOURCE_ROOT")) + "/tests/opatIO/test.opat";
+std::string EXAMPLE_FILENAME = std::string(getenv("MESON_SOURCE_ROOT")) + "/tests/opatIO/synthetic_tables.opat";
 
 /**
  * @file opatIOTest.cpp
@@ -32,6 +34,9 @@ TEST_F(opatIOTest, Constructor) {
     OpatIO opatIO(EXAMPLE_FILENAME);
 }
 
+/**
+ * @test Verify the header is read correctly.
+ */
 TEST_F(opatIOTest, Header) {
     OpatIO opatIO(EXAMPLE_FILENAME);
     Header header = opatIO.getHeader();
@@ -39,42 +44,60 @@ TEST_F(opatIOTest, Header) {
     EXPECT_EQ(header.numTables, 20);
     EXPECT_EQ(header.headerSize, 256);
     EXPECT_EQ(header.indexOffset, 416416);
-    EXPECT_EQ(std::string(header.creationDate), "Feb 16, 2025");
-    EXPECT_EQ(std::string(header.sourceInfo), "no source provided by user");
-    EXPECT_EQ(std::string(header.comment), "default header");
+    EXPECT_EQ(std::string(header.creationDate), "Feb 17, 2025");
+    EXPECT_EQ(std::string(header.sourceInfo), "utils/opatio/utils/mkTestData.py");
+    EXPECT_EQ(std::string(header.comment), "Synthetic Opacity Tables");
+    EXPECT_EQ(header.numIndex, 2);
 }
 
+/**
+ * @test Verify the number of index values is correct. Also check the byte position and index vector
+ */
 TEST_F(opatIOTest, TableIndex) {
     OpatIO opatIO(EXAMPLE_FILENAME);
     std::vector<TableIndex> tableIndex = opatIO.getTableIndex();
     EXPECT_EQ(tableIndex.size(), 20);
-    EXPECT_EQ(tableIndex[0].X, 0.1);
-    EXPECT_EQ(tableIndex[0].Z, 0.001);
+    EXPECT_EQ(tableIndex[0].index.at(0), 0.1);
+    EXPECT_EQ(tableIndex[0].index.at(1), 0.001);
     EXPECT_EQ(tableIndex[0].byteStart, 256);
     EXPECT_EQ(tableIndex[0].byteEnd, 21064);
 }
 
+/**
+ * @test Verify the maxQDepth (for caching)
+ */
 TEST_F(opatIOTest, MaxQDepth) {
     OpatIO opatIO(EXAMPLE_FILENAME);
-    EXPECT_EQ(opatIO.getMaxQDepth(), 10);
+    EXPECT_EQ(opatIO.getMaxQDepth(), 20);
     opatIO.setMaxQDepth(5);
     EXPECT_EQ(opatIO.getMaxQDepth(), 5);
 }
 
+/**
+ * @test Verify the Unload function
+ */
 TEST_F(opatIOTest, Unload){
     OpatIO opatIO(EXAMPLE_FILENAME);
     EXPECT_NO_THROW(opatIO.unload());
     EXPECT_FALSE(opatIO.isLoaded());
 }
 
+/**
+ * @test Verify the lookupTableID function
+ */
 TEST_F(opatIOTest, LookupTableID) {
     OpatIO opatIO(EXAMPLE_FILENAME);
-    EXPECT_EQ(opatIO.lookupTableID(0.321053, 0.0116842), 7);
+    std::vector<double> index = {0.321053, 0.0116842};
+    EXPECT_EQ(opatIO.lookupTableID(index), 7);
 }
 
+/**
+ * @test Verify the GetTable function by checking the first 2x2 square of the table
+ */
 TEST_F(opatIOTest, GetTable) {
     OpatIO opatIO(EXAMPLE_FILENAME);
-    OPATTable tab = opatIO.getTable(0.1, 0.001);
+    std::vector<double> index = {0.1, 0.001};
+    OPATTable tab = opatIO.getTable(index);
     EXPECT_EQ(tab.N_R, 50);
     EXPECT_EQ(tab.N_T, 50);
     EXPECT_DOUBLE_EQ(tab.logR[0], -8.0);
@@ -83,4 +106,28 @@ TEST_F(opatIOTest, GetTable) {
     EXPECT_DOUBLE_EQ(tab.logKappa[0][1], 1.8028572256396647);
     EXPECT_DOUBLE_EQ(tab.logKappa[1][0], 1.8783385110582342);
     EXPECT_DOUBLE_EQ(tab.logKappa[1][1], 1.1005312934444582);
+}
+
+
+
+/**
+ * @test Verify the GetTable function by computing the checksum of the first table and 
+ * comparing it to the stored checksum
+ */
+TEST_F(opatIOTest, Checksum) {
+    OpatIO opatIO(EXAMPLE_FILENAME);
+    std::vector<double> index = {0.1, 0.001};
+    TableIndex tableIndex = opatIO.getTableIndex(index);
+    std::vector<unsigned char> hash = opatIO.computeChecksum(index);
+    std::string hexRepr = picosha2::bytes_to_hex_string(hash);
+
+    std::vector<unsigned char> storedHashVec(tableIndex.sha256, tableIndex.sha256 + 32);
+    std::string storedHexRepr = picosha2::bytes_to_hex_string(storedHashVec);
+    EXPECT_EQ(hexRepr, storedHexRepr);
+}
+
+TEST_F(opatIOTest, ChecksumAll) {
+    OpatIO opatIO(EXAMPLE_FILENAME);
+    opatIO.setMaxQDepth(5);
+    EXPECT_TRUE(opatIO.validateAll());
 }
\ No newline at end of file
diff --git a/tests/opatIO/synthetic_tables.opat b/tests/opatIO/synthetic_tables.opat
new file mode 100644
index 0000000..b65f569
Binary files /dev/null and b/tests/opatIO/synthetic_tables.opat differ