1/2*x1/Pi^(1/2)/(x0^2+x1^2+x2^2)^(3/2)*qi+1/2*x2/Pi^(1/2)/(x0^2+x1^2+x2^2)^(3/2)*qj-1/2*x0/Pi^(1/2)/(x0^2+x1^2+x2^2)^(3/2)
