Cleaving Bi2212 is common to prepare samples for STM and to make ultrathin films (e.g., Novoselov et al., PNAS 102, 10451–10453 (2005) and Huang et al. ACS nano 9, 10612–10620 (2015)). But, has someone calculated the forces between the different layers in an unit cell of Bi-2212? It would be very good to quantify these forces values for model calculations.