Q.Draw (100), (010) and (001) planes.

(100), (010) and (001) are the three mutually perpendicular faces of a cubic unit cell, each cutting only one of the three crystallographic axes (a, b, c) at unit distance and running parallel to the other two.

Miller indices (hkl) describe crystal planes in terms of the reciprocals of the intercepts a plane makes on the three crystallographic axes (a, b, c), cleared of fractions. For a cubic unit cell with mutually perpendicular axes a, b, c of equal length:

• The (100) plane cuts the a-axis at 1 unit but is parallel to the b- and c-axes (never meets them, i.e., infinite intercept). This is the cube face perpendicular to the a-axis - visually, it is the left or right face of the cube if a runs left-right.
• The (010) plane cuts the b-axis at 1 unit and is parallel to the a- and c-axes. This is the cube face perpendicular to the b-axis.
• The (001) plane cuts the c-axis at 1 unit and is parallel to the a- and b-axes. This is the cube face perpendicular to the c-axis (typically drawn as the top or bottom face). …