diff --git a/Lecture4.ipynb b/Lecture4.ipynb
index 76d851a..f3cb633 100644
--- a/Lecture4.ipynb
+++ b/Lecture4.ipynb
@@ -912,8 +912,7 @@
    "source": [
     "#Code block \n",
     "\n",
-    "\n",
-    "    "
+    "\n"
    ]
   },
   {
diff --git a/slides/MLforMaterials_Lecture5_Classical.pdf b/slides/MLforMaterials_Lecture5_Classical.pdf
new file mode 100644
index 0000000..ae8b8a9
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diff --git a/slides/MLforMaterials_Lecture6_NN.pdf b/slides/MLforMaterials_Lecture6_NN.pdf
new file mode 100644
index 0000000..db20f63
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