How can i calculate miller indices for first bragg's peak

n(lambda)=2dSin(theta) Assuming first order diffraction (n=1) and by putting all the know value you will get the value of d(distance between two planes). From the value of d and th...

for a fcc lattice , miller indices for the first bragg's peak.....?

that's the neat part...you can't...you can just get d