[gmx-users] the order parameter obtained by g_angle

Dear all, Who can tell me how the order parameter obtained by g_angle is defined? or where can I find the details? Thanks very much. -- gmx-users mailing listgmx-users@gromacs.org http://lists.gromacs.org/mailman/listinfo/gmx-users Please search the archive at http://www.gromacs.org/Support

[gmx-users] problem of tabulated bonded potential

Dear all gmxers, I meet some problems when I use the tabulated bonded potential. My original function is a sum of An*cos(x)^n (n=1-8).For short here I replaced it by cos(x). if f(x)=cos(x),then -f'(x)=sin(x).and the numberical derivative -f'(x)=-(y(n+1)-y(n-1))/2. but there are great discrepancy

[gmx-users] Re: problem of tabulated bonded potential

XAvier, thanks for your reply. the numberical derivative -f'(n)=dy/dx=-(y(n+1)-y(n-1))/(n+1)-(n-1). so -f'(n)=-(y(n+1)-y(n-1))/2. Is it wrong? On Nov 9, 2010, at 7:12 AM, Z.Xiao wrote: > Dear all gmxers, > I meet some problems when I use the tabulated bonded potential. > M