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