what is the wavelength?
distance between two peaks
what is theta?
angle between incident and diffracted wave
what is path difference for constructive interference?
n x wavelength (n=1 so just wavelength)
constructive v destructive interference
destructive = where the path length isnt an integer no. of wavelengths
why do systematic absences occur?
because of destructive interference of reflections from certain planes, or other translational symmetry elements
equation for body centred miller indices to be allowed in diffraction pattern
h+k+l = 2n
equation for face centred miller indices to be allowed in diffraction pattern
h,k,l all odd or all even