diff --git a/physionet/metrics/__init__.py b/physionet/metrics/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/physionet/metrics/dimensions.py b/physionet/metrics/dimensions.py
new file mode 100644
index 0000000..ebbe894
--- /dev/null
+++ b/physionet/metrics/dimensions.py
@@ -0,0 +1 @@
+# TODO: add tools for getting metrics from dimensions.ai
diff --git a/physionet/metrics/openalex.py b/physionet/metrics/openalex.py
new file mode 100644
index 0000000..e69de29