diff --git a/test_problems/diamondSurf/diamond.cti b/test_problems/diamondSurf/diamond.cti
index 08bc3f32a..0df40af0f 100644
--- a/test_problems/diamondSurf/diamond.cti
+++ b/test_problems/diamondSurf/diamond.cti
@@ -20,7 +20,7 @@ ideal_gas(name = 'gas',
 #------------- bulk diamond -------------------------------------
 
 pure_solid(name = 'diamond',
-                     elements = 'C',
+                     elements = 'H C',
                      density = (3.52, 'g/cm3'),
                      species = 'C(d)')
 
diff --git a/test_problems/diamondSurf/diamond_blessed.xml b/test_problems/diamondSurf/diamond_blessed.xml
index c32c23a1a..79a1671e7 100644
--- a/test_problems/diamondSurf/diamond_blessed.xml
+++ b/test_problems/diamondSurf/diamond_blessed.xml
@@ -17,7 +17,7 @@
 
   <!--    phase diamond     -->
   <phase dim="3" id="diamond">
-    <elementArray datasrc="elements.xml">C</elementArray>
+    <elementArray datasrc="elements.xml">H C</elementArray>
     <speciesArray datasrc="#species_data">C(d)</speciesArray>
     <thermo model="SolidCompound">
       <density units="g/cm3">3.52</density>
diff --git a/test_problems/diamondSurf/tdia_a.py b/test_problems/diamondSurf/tdia_a.py
new file mode 100755
index 000000000..23df6bc1b
--- /dev/null
+++ b/test_problems/diamondSurf/tdia_a.py
@@ -0,0 +1,31 @@
+from Cantera import *
+import math
+
+g, dbulk = importPhases('diamond.cti',['gas','diamond'])
+
+d = importInterface('diamond.cti','diamond_100',phases = [g, dbulk])
+ns = d.nSpecies()
+mw = dbulk.molarMasses()[0]
+
+t = 1200.0
+x = g.moleFractions()
+p = 20.0*OneAtm/760.0
+g.setState_TPX(t, p, x)
+ih = g.speciesIndex('H')
+
+xh0 = x[ih]
+f = open('d.csv','w')
+#writeCSV(f, ['H mole Fraction', 'Rate']+d.speciesNames())
+for n in range(20):
+    x[ih] /= 1.4
+    g.setState_TPX(t, p, x)
+    d.advanceCoverages(10.0)
+    cdot = d.netProductionRates(phase = dbulk)[0]
+    mdot = mw*cdot
+    rate = mdot/dbulk.density()
+    print x[ih], rate*1.0e6*3600.0
+    writeCSV(f,[x[ih],rate]+list(d.coverages()))
+f.close()
+
+
+