Axilrod-Teller interaction
The Axilrod-Teller interaction for three-body interactions is given by (Ref. 1):
where are the lengths of the sides and are the angles of the triangle formed by the three atoms.
The Axilrod-Teller interaction for three-body interactions is given by (Ref. 1):
where  are the lengths of the sides and 
 are the angles of the triangle formed by the three atoms.