Classification of seven-vertex solutions of the coloured Yang-Baxter equation

Abstract

In this paper all seven-vertex type solutions of the coloured Yang-Baxter equation dependent on spectral as well as coloured parameters are given. It is proved that they are composed of five groups of basic solutions, two groups of their degenerate forms up to five solution transformations. Moreover, all solutions can be claasified into two types called Baxter type and free-fermion type.