Hi Zhichao,
Yes, SNAP has provisions for detecting aromatic stacking interactions. Try the (currently undocumented) option --get-stack to see if it gets what you want.
The output is in format;
1 U/G A.U2647 A.G2648 1.0 3.32 6where the last three values are the area of overlap in Å2, vertical distance in Å, and angle between the two planes.
I welcome your suggestions to revise this functionality in order to better fit your needs.
Best regards,
Xiang-Jun