0.08673 - 0.2838 \chi_+ - 0.08817 \chi_- - 10.79 \eta^2 + 2.238 \eta \chi_+ + 0.3544 \eta \chi_- + 0.187 \chi_+ \chi_- + 0.2696 \chi_-^2 + 71.95 \eta^3 - 4.639 \eta^2 \chi_+ - 2.673 \eta \chi_-^2 - 0.04592 \chi_+^2 \chi_- - 138.5 \eta^4 - 3.162 \eta^2 \chi_+ \chi_- + 6.734 \eta^2 \chi_-^2