PHY.K02UF Molecular and Solid State Physics

The first Brillouin zone of a simple cubic lattice

    

$\vec{k}=u\vec{b}_1+v\vec{b}_2+w\vec{b}_3$ : $(u,v,w)$

  Symmetry points  (u,v,w)  [kx,ky,kz]  Point group    
  Γ: (0,0,0)    [0,0,0]

m3m

  R: (1/2,1/2,1/2)    [π/a,π/a,π/a]

m3m

  X: (0,1/2,0)    [0,π/a,0]

4/mmm

  M: (1/2,1/2,0)    [π/a,π/a,0]

4/mmm

$\large \overline{\Gamma X}=\frac{\pi}{a},$ $\large \overline{\Gamma M}=\frac{\sqrt{2}\pi}{a},$ $\large \overline{\Gamma R}=\frac{\sqrt{3}\pi}{a}$

  Symmetry lines    Point group  
  Δ: (0,v,0)  0 < v < 1/2  

4mm

  T: (1/2,1/2,w)  0 < w < 1/2  

4mm

  Λ: (w,w,w)  0 < w < 1/2  

3m

  Σ: (u,u,0)  0 < u < 1/2  

mm2

  S: (u,1/2,u)  0 < u < 1/2  

mm2

  Z: (u,1/2,0)  0 < u < 1/2  

mm2

The real space and reciprocal space primitive translation vectors are:

\begin{equation} \large \vec{a}_1=a\hat{x},\quad \vec{a}_2=a\hat{y},\quad\vec{a}_3=a\hat{z},\\ \large \vec{b}_1=\frac{2\pi}{a}\hat{k}_x,\quad \vec{b}_2=\frac{2\pi}{a}\hat{k}_y,\quad\vec{b}_3=\frac{2\pi}{a}\hat{k}_z. \end{equation}

Cut-out pattern to make a paper model of the simple cubic Brillouin zone.