Any polyhedron or geodesic structure that has a single dihedral angle throughout its geometry. Many basic polyhedra have a single dihedral angle, like a cube, dodecahedron or Icosahedron, but as frequencies and complexity increases it becomes very difficult or impossible to produce mono-dihedral forms.
An example is a 2v icosahedral geodesic sphere which normally has two dihedral angles 161.971 degrees, equilateral to pentagon and 157.541 degrees pent to pent. The mono dihedral version has dihedral angles of 159.897 degrees for all edges. Mono dihedral domes are easier to mass produce because of the limited number of machining operations.
Chord factors for a mono 2v are: Eql = 0.636859 Pent = 0.558626
Subtly different from the standard 2v: Eql = 0.618034 Pent = 0.546533