diff --git a/GSASII/atmdata.py b/GSASII/atmdata.py
index 553c47f4..4a1126b1 100644
--- a/GSASII/atmdata.py
+++ b/GSASII/atmdata.py
@@ -1379,6 +1379,7 @@
     'Re_':   {'Mass':186.207,'SL':[    .92,      0],'SA':        89.7},
     'Os_':   {'Mass':  190.2,'SL':[   1.07,      0],'SA':        16.0},
     'Ir_':   {'Mass': 192.22,'SL':[   1.06,      0],'SA':        425.},
+    'Ir_193':{'Mass':192.963,'SL':[  0.971,      0],'SA':        111.}, #Hannon, Gibbs, Takagi (2018) 10.1107/S1600576718006064
     'Pt_':   {'Mass': 195.09,'SL':[    .96,      0],'SA':        10.3},
     'Au_':   {'Mass':196.967,'SL':[   .790,      0],'SA':       98.65},
     'Au_197':{'Mass':196.967,'SL':[   .790,      0],'SA':       98.65},