<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div>Hi Margarita,</div><div><br></div><div>As all your surfaces have four sides and your volumes six sides, </div><div>you can let Gmsh do most of the work for you: no need of indicating the loop of corners/surfaces.</div><div><br></div><div>I guess you had given a bad loop or forgotten to Recombine one surfaces.</div><div>See the attached corrected file.</div><div><br></div><div>Regards,</div><div>Ruth </div><div><br></div><div></div></body></html>