ompute a global similarity of structures based on the average</span>
<span class="sd">    similarity of local atomic environments in the structure. More precisely,</span>
<span class="sd">    returns the similarity kernel K as:</span>

<span class="sd">    .. math::</span>
<span class="sd">        K(A, B) = \\frac{1}{N M}\sum_{ij} C_{ij}(A, B)</span>

<span class="sd">    where :math:`N` is the number of atoms in structure :math:`A`, :math:`M` is</span>
<span class="sd">    the number of atoms in structure 