Hi, I wrote a conversion tool (using meshio) to export paraview's vtu format to gmsh so that I could import to .xml format. It seems to be working quite well, except that all of the prisms have negative jacobians and Linearising them has no effect. The commands I used as follows: NekMesh DSI020CALb_vmtk_decimate_trim_ext2_mesh.msh DSI020CALb_nektar.xml NekMesh -m jac:extract DSI020CALb_nektar.xml DSI020CALb_nektar_jac_export.xml FieldConvert DSI020CALb_nektar_jac_export.xml DSI020CALb_nektar_jac_export.vtu NekMesh -m linearise:invalid DSI020CALb_nektar.xml DSI020CALb_nektar_lin.xml There are 3180 prism elements and they all give negative jacobians, and this doesn't change with linearization. Is there a node ordering issue? is there an easy way to fix this? any hints on where to start digging to resolve? Regards, ~Kurt Sansom -- Kurt Sansom Graduate Research Assistant Multiphase & Cardiovascular Flow Lab University of Washington