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+## Units will be an array
+
+  units:["Hartree",1.0] # 1st entry: label of the unit for human reading. 2nd entry: Conversion constant to the default unit.
+  
+  units:["eV", 0.036749]
+  
+  units:["Bohr",1.0]
+  
+  units:["Angstrom",1.8897]
+  
+  units:["kcal/mol", 0.0015936]
+  
+  units:["Angstrom/(atomic time)", 1.8897]
+  
+  units:["cm-1",  2.1948e+05]
+  
+  units:["THz", 6579.8]
+  
+  units:["amu", 1822.89]
+  
+  units:["seconds": 2.418884326509e-17]
+  
+ 
+  
+ 
+  
+## Defult units use unless specified
+
+  Default units use atomic units for everything
+
+  distance: atomic units (bohrs)
+  
+  velocity:bohrs/(au seconds)
+  
+  forces: bohrs/(au seconds^2)
+  
+## Put the units close to quantities:
+
+    eg.
+    coords:{ units:["Bohr",2.2],
+             xyz:[...] }
+             
+    total_enery:{value: 23,
+                 units:[...]}
+                 
+## If the "_" pointers are implemented then the units can be specified one level above follows
+
+    eg. 
+          coords:{ xyz:[...]}
+          coords_units:[...]