Rg Calculator for SAS

Choose the geometrical shape and the lengths of the semi-axes in the x-, y- and z-directions (rx,ry,rz). The values of the radius of gyration Rg and the zero-angle intensity I(0) will be calculated. Units are arbitrary and in metric dimensions (in small-angle scattering (SAS) usually in Å or nm). In case of models extending infinitely in the 3rd dimension Rg of the cross-section (circle, ellipse or rectangle, rz is set to 0), and in case of models spreading infinitely in two dimensions Rg of the thickness (line, rx and ry are set to 0) will be calculated, respectively.

sphere (rx=ry=rz), rotat.ellipsoid (rx=ry,rz), ellipsoid (rx,ry,rz)
circ.cylinder (rx=ry,rz=c/2), ellipt.cyinder (rx,ry,rz=c/2), cube (rx=a/2, ry=b/2, rz=c/2)
circle (rx=ry,rz=0), ellipse (rx,ry,rz=0), rectangle (rx=a/2,ry=b/2,rz=0), line (rx=ry=0,rz=c/2)


rx : ry : rz :

Radius of gyration: I(0):


Author: M.Kriechbaum, IBR (2000), e-mail: manfred.kriechbaum@oeaw.ac.at