Hi there,

I read the theory of "Spatial orientation correlation functions" in help document.

An orientation correlation function describes whether there is a correlation between the orientation of a molecule or side group, and a specified direction, for instance the x-axis, or the orientation of another molecule. The orientation correlation function is usually described in terms of an order parameter S, such that a value of zero corresponds to no order, and a value of 1 corresponds to perfect alignment. Legendre polynomials provide convenient order parameters.

I'd like to calculate the S order parameter of surfactant molecules(DTA) along specified direction, for instance the z-axis, what should I do for the "Spatial orientation correlation functions" set in the forcite analysis?

P2=(3*(cosθ)^2-1)/2

If all the surfactant molecules are parallel to this direction, angle θ=0, P2=1

If all the molecules are random, no direction preference, P2=0

where is θ is the angle between two distance monitor, how to define a z direction and calculate the S order parameter of the surfactant molecules?

Best Regards

william