  Positions of a charged particle's equilibrium orbits and spatial regions
where the chaos bound is violated are found through circular motions of the
particle around charged Taub-NUT black holes. Lyapunov exponent is gotten by
calculating eigenvalues of a Jacobian matrix in a phase space $(r,\pi_r)$. When
the particle's charge is fixed, the positions of the equilibrium orbits
gradually move away from the event horizons with the increase of the angular
momentum.The result shows that the bound is violated in the near-horizon
regions and at a certain distance from the horizons when the charge and NUT
parameter are fixed. The spatial regions increase with the increase of the NUT
parameter's value.
