Cruz, A.Fernández Pérez, Luis AntonioÍñiguez, D.Tarancón, A.2023-06-202023-06-201996-05-020370-269310.1016/0370-2693(96)00235-3https://hdl.handle.net/20.500.14352/60102© 1996 Published by Elsevier Science B.V. We wish to thank Juan J. Ruiz-Lorenzo for useful discussions. Partially supported by CICyT AEN93-0604-C03, AEN94-0218, AEN951284E, and ERBCHRXCT920051. D.I. is a MEC Fellow.We have made a study of several update algorithms using the XY model. We find that sequential local overrelaxation is not ergodic at the scale of typical Monte Carlo simulation time. We have introduced a new multisite microcanonical update method, which yields results compatible with those of random overrelaxation and the microcanonical demon algorithm, which are very much slower, all being incompatible with the sequential overrelaxation results.engjournal articlehttp://doi.org/10.1016/0370-2693(96)00235-3http://www.sciencedirect.comopen access5351-73Monte-Carlo simulationLattice Gauge-theoriesFermions.Física (Física)Física-Modelos matemáticos22 Física