Dear Gmx-users, I created a box size 4 4 2 and named layer.gro. Then "genconf" was used to doulble this box: genconf -f layer.gro -o 2layers.gro -nbox 1 1 2 -dist 0 0 8 However, the copied box has the same direction as the original box. Could you please help me to rotate 180 degrees the copied one? Thank you very much. Best regards, Cuong