Point Group of a pattern I need to determine the point group of the following patterns: !enter image description here I think the one on the left is $D_1$ and the one on the right is $D_2$

To determine which wallpaper group you have, first identify the unit cell and symmetry operations for your images:

!Symmetry and unit cell

Then use the Wallpaper group diagram:

!Wallpaper group diagram

Both images have a maximum of 2-fold rotations and simple reflections. The left image has no perpendicular reflections, making it _pmg_. The right image has perpendicular reflections with an off-axis rotocenter, making it _cmm_.

Both of these latices have $D_2$ point groups at the center of the cell, as well as lower-order point groups at other points.