Candidate benchmark problems can also feature some of the following characteristics:
a) a hyperbolic equilibrium point with (i) only real, (ii) only complex, or (iii) real and complex eigenvalues;
b) a non-hyperbolic equilibrium point (e.g. Lindemann);
c) a stable limit cycle (e.g. Semenov);
d) a bifurcating cascade of limit cycles of higher periods leading to chaotic behaviors (e.g. Lorenz or Franceschini-Tebaldi);
e) linear or nonlinear diffusion, as well as differential diffusion.