Critical temperature of the Ising ferromagnet on the fcc, hcp, and dhcp lattices

By an extensive Monte-Carlo calculation together with the finite-size-scaling and the multiple histogram method, the critical coupling constant (Kc=J/kBTc) of the Ising ferromagnet on the fcc, hcp, and double hcp (dhcp) lattices were obtained with unprecedented precision: Kcfcc=0.1020707(2), Kchcp=0.1020702(1), and Kcdhcp=0.1020706(2). The critical temperature Tc of the hcp lattice is found to be higher than those of the fcc and the dhcp lattice. The dhcp lattice seems to have higher Tc than the fcc lattice, but the difference is within error bars.