Dear all, I wonder the which number I should give to feed the -sgang1 and -sgang2 if I calculate the water tetrahedral order in a simple lipid bilayer system. I searched extensively and read the source code hydorder.c but still have no idea in this case. However, Phi(i,j) in Eqn(3) of Chau and Hardwick 1998 Mol. Phys. paper seems okay to me. Best regards, Yao