planar domain wall between the regions with almost homogeneous Abelian self-dual and anti-self-dual gluon fields. Chromomagnetic and chromoelectric fields are orthogonal to each other on the wall, see Fig.\[Fig:single\_kink\]. Far from the wall, the topological charge density is constant, its absolute value is equal to the value of the gluon condensate. The topological charge density vanishes on the wall. The upper plot shows the profiles of the components of the chromomagnetic and chromoelectric fields corresponding to the Bloch domain wall – the chromomagnetic field flips in the direction parallel to the wall plane.

![Kink profile in terms of the components of the chromomagnetic and chromoelectric field strengths (upper plot), and a two-dimensional slice for the topological charge density in the presence of a single kink measured in units of $g^2F^b_{\alpha\beta}F^b_{\alpha\beta}$ (lower plot). Here $\omega$ is the angle between the chromomagnetic and chromoelectric fields, $\cos\omega=F^a_{\mu\nu}\tilde F^a_{\mu\nu}/F^b_{\alpha\beta}F^b_{\alpha\beta}$. The three-dimensional planar domain wall separates the four-dimensional regions filled with the self-dual (blue color) and anti-self-dual (red color) Abelian covariantly constant gluon fields. The chromomagnetic and chromoelectric fields are orthogonal to each other inside the wall (green color). []{data-label="Fig:single_kink"}](kink){width="75mm"}

![Kink profile in terms of the components of the chromomagnetic and chromoelectric field strengths (upper 