This is available only for hexa elements and is the measurement of the twisting of the element from the ideal shape. For this the Jacobian determinants will be calculated at r,s,t=-1,0,1 of the natural coordinate system of the element (27 node positions). The distortion is 27 times the minimum of all absolute determinants divided by the sum of all 27 absolute determinants (0 if all Jacobian determinants are 0).