The sliced cylinder strategy biases the system to occupy the inner space of the membrane spanning cylinder along the normal to the bilayers, with no restrictions imposed on the XY planes. Using this technique, Hub and collaborators showed that small pores in single bilayers were nearly cylindrical, while larger ones (radius > 1.2nm) revealed a nearly ideal toroidal shape. Systems used along this work belong to the category of small ones (17x17nm) with a maximum fusion pore radius < 1nm (see figure ) and were modeled as toroidal.