diff --git a/massive_star/convert_large_to_small.py b/massive_star/convert_large_to_small.py
index 1e66b95..19f7f54 100644
--- a/massive_star/convert_large_to_small.py
+++ b/massive_star/convert_large_to_small.py
@@ -1,13 +1,24 @@
 import numpy as np
-from pynucastro.networks.rate_collection import Composition
+from pynucastro.nucdata import Composition
 import argparse
 
 implemented_networks = {
     "aprox19": ['h1', 'he3', 'he4', 'c12', 'n14', 'o16', 'ne20', 'mg24', 
                   'si28', 's32', 'ar36', 'ca40', 'ti44', 'cr48', 'fe52', 
                   'fe54', 'ni56', 'n'],
+    "massive-star-medium": ["n", "h1", "he4", "c12", "o16",
+                        "ne20", "na23", "mg23", "mg24", "al27",
+                       "si27", "si28", "si30", "p29", "p31", 
+                       "s30", "s32", "s34", "cl33", "cl35",
+                       "ar34", "ar36", "ar38", "k37", "k39", 
+                       "ca38", "ca40", "c42", "sc41", "sc43",
+                       "ti42", "ti44", "ti46", "v45", "v47", "v49", 
+                       "cr46", "cr48", "cr50", "cr52", 
+                       "mn49", "mn51", "mn53",
+                       "fe50", "fe52", "fe54", "fe56", 
+                       "co53", "co55", "co57", "ni56", "ni58", "cu59", "zn60"],
 }
-# the aprox19 nuclei list excludes p_nse. We'll deal with that split by later setting 'p' to 0
+# both typically include p_nse. We'll deal with that split by later setting 'p' to 0
 
 
 def main(file_name, new_file_name, network):