3.1.6 IBRAV=4 simple hexagonal lattice(単純立方格子)

CELLDM(1) $=a$, CELLDM(3) $=c/a$, $\Omega=\sqrt{3} a^{2}c/2$ ( ${\bf a}_{1}\cdot{\bf a}_{2}=-a^{2}/2$)
$({\bf a}_{1},{\bf a}_{2},{\bf a}_{3})= ({\bf x},{\bf y},{\bf z}) \left( \beg... ...a}{2} & 0 \\ 0 & \frac{\sqrt{3}a}{2} & 0 \\ 0 & 0 & c \end{array} \right)$
$({\bf b}_{1},{\bf b}_{2},{\bf b}_{3})= \frac{2 \pi}{a} ({\bf x},{\bf y},{\bf ... ...}}{3} & \frac{2 \sqrt{3}}{3} & 0 \\ 0 & 0 & \frac{a}{c} \end{array} \right)$
Calculation example(計算例)：GaN(Würtzite)、graphite(hcp)