diff --git a/openmc/data/thermal.py b/openmc/data/thermal.py
index cd44f21f95..be35da517b 100644
--- a/openmc/data/thermal.py
+++ b/openmc/data/thermal.py
@@ -33,6 +33,7 @@ _THERMAL_NAMES = {'al': 'c_Al27', 'al27': 'c_Al27',
                   'orthod': 'c_ortho_D', 'dortho': 'c_ortho_D',
                   'orthoh': 'c_ortho_H', 'hortho': 'c_ortho_H',
                   'ouo2': 'c_O_in_UO2', 'o2-u': 'c_O_in_UO2', 'o2/u': 'c_O_in_UO2',
+                  'sio2': 'c_SiO2',
                   'parad': 'c_para_D', 'dpara': 'c_para_D',
                   'parah': 'c_para_H', 'hpara': 'c_para_H',
                   'sch4': 'c_solid_CH4', 'smeth': 'c_solid_CH4',