[gmx-users] How deuterium order parameters computed?

Hi Everyone, I have a question about the implementation details of g_order. When I was reading literatures, I found several interpretations of how the deuterium order parameters are computed. One is calculate S_{ij} first, then S_{CD} = \frac{2}{3} S_{xx} + \frac{1}{3} S_{yy}. Another approach

Re: [gmx-users] How deuterium order parameters computed?

I believe the two approaches you list are identical; the prefactors of 2/3 and 1/3 in the equation specified assume a tetrahedral symmetry. This relation is often just stated as fact (since it is relatively straightforward to derive) but there is a nice write up of it by J.-P. Douliez, A.