calcining {HEAD ~ said crystalline composition} at {TAIL ~ a temperature} of from about 200° C. to about 600° C., 
at
calcining { HEAD ~ said crystalline composition } at { TAIL ~ a temperature } of from about 200 ° C. to about 600 ° C. ,
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH