Hi All,

I am calculating hexorder/bond using lammps which gives me real and imaginary number for a 2D system. In order to calculate average q6 I use following commands:

compute q6 sol hexorder/atom degree 6 nnn 6

variable normq6 atom sqrt(c_q6[1]^2+c_q6[2]^2)

compute cmeanq6 sol reduce ave v_normq6

fix 2 sol ave/time 1000 1 1000 c_ cmeanq6 file Q6ave.dat ave running overwrite

however, the value that I get is non-zero for high temperature system with liquid-like RDF.

Am I missing a point?

Thanks for your help.

Alireza

Hi All,

I am calculating hexorder/bond using lammps which gives me real and imaginary number for a 2D system. In order to calculate average q6 I use following commands:

it is hexorder/atom, not hexorder/bond

compute q6 sol hexorder/atom degree 6 nnn 6

variable normq6 atom sqrt(c_q6[1]^2+c_q6[2]^2)

compute cmeanq6 sol reduce ave v_normq6

fix 2 sol ave/time 1000 1 1000 c_ cmeanq6 file Q6ave.dat ave running overwrite

however, the value that I get is non-zero for high temperature system with liquid-like RDF.

Am I missing a point?

yes. there is a difference between computing the norm for each atom and averaging over it and computing the average of the real and imaginary parameters and then taking the norm of that. the first will give you the average local order, while the second will give you the average global order parameter. the first is has to be larger than the second by simple geometric and mathematical considerations.

axel.