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