The reactants can be heated between about 650° C. and {HEAD ~ 670° C.} to produce {TAIL ~ type II clathrates} Na24Si136 and K24Si136 
The reactants can be heated between about 650 ° C. and { HEAD ~ 670 ° C. } to produce { TAIL ~ type II clathrates } Na24Si136 and K24Si136
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH