## Materials Science and Engineering: An Introduction

the point represent be $(-1,0,0)$ $(0,-1,0)$ $(0,1,0)$
$x_{1}=y_{1}=z_{1}=0$ . Tetragonal unit cell $a = b \ne c$ Now the point $x_{2}=a$ $y_{2}=0b=0$ and $z_{2}=0c=0$ vector length =$\sqrt{x^2+y^2+z^2}=\sqrt{a^2}=a$ Then the point will be $(-1,0,0)$ $(0,-1,0)$ $(0,1,0)$