I'm using SfePy to solve a problem.Firstly, I creat a simple cube by Gmsh and save as my.mesh file.

Now I am using sfepy/examples/multi_physics/biot.py to calculate.but it something wrong.

Then I open the "/meshes/3d/cube_medium_hexa.mesh",in the  "cube_medium_hexa.mesh" file,it consists  Vertices and Hexahedra.But in my mesh file,it only consists Vertices,Edges and  Triangles,no Hexahedra. When I run the biot.py, there aren't any results I want. How can I save .mesh file including Hexahedra? I think it is the main probelm.