1. The Kagome lattice consists of corner-sharing triangles and is characterised by a large degree of geometric frustration, which becomes visible for instance in an antiferromagnetic Heisenberg model: while two of the three spins can be antiparallel, the third one is frustrated—both possible configurations will always contain one good and bad bond and are hence degenerate. (https://www.manybody.phy.cam.ac.uk/Research/kagome)