begin mathsize 48px style left parenthesis h k l right parenthesis end style

h , k , l= Miller Indices ;    

begin mathsize 36px style U equals fraction numerator N subscript A M z to the power of plus z to the power of minus e squared over denominator 4 πε subscript straight o straight r end fraction open parentheses 1 minus 1 over n close parentheses end style

U=Lattice Energy ; NA= Avogadro Number ; M= Madelung Constant ; z+ & z- = Charge on the Cation & the Anion;

e = Change of an electron; n= Born Exponent ; r =Inter ionicDistance; εo = Permitivity of free Space; 

begin mathsize 48px style n lambda equals 2 d subscript h k l end subscript sin theta end style

n = An integer ;   λ = Wavelength of the incident light ; dhkl= Lattice Spacing ; θ = Angle of incidence ; 

begin mathsize 36px style d subscript h k l end subscript equals fraction numerator a over denominator square root of h squared plus k squared plus l squared end root end fraction end style

dhkl= Lattice Spacing ; a = Lattice Constant ; h , k , l = Miller Indices;

begin mathsize 36px style 1 over d squared equals fraction numerator h squared plus k squared over denominator a squared end fraction plus space l squared over c squared end style

d= Interplanar Spacing ; h , k , l = Miller Indices; a ,c = Lattice Constants

begin mathsize 36px style t subscript bevelled 1 half end subscript space. space log open parentheses W subscript i n i end subscript over W subscript F i n end subscript close parentheses space equals space T space. space log left parenthesis 2 right parenthesis space end style

t1/2 = Half-life of the isotope; T = Time taken for the specific decay ; Wini = Initial amount of the radioactive isotope; Wfin = Final amount of the radioactive isotope

begin mathsize 48px style t subscript bevelled 1 half end subscript equals space 0.693 divided by lambda end style

t1/2 = Half Life of Radioactive elment; λ = Decay Constant of the radioactive element

begin mathsize 36px style lambda equals fraction numerator 2.303 over denominator t end fraction log open parentheses n subscript 0 over n close parentheses end style

λ = Radioactive Decay Constant or Disintegration Constant; t = Time interval for which radioelement is present ;  

n0 = Initial number of atoms ; n= Final number of atoms.

begin mathsize 48px style Z subscript e f f end subscript equals Z minus space sigma space end style

Z = Effective nuclear charge; Z = Atomic Number ; σ = Shielding