Available Model Functions

The available functional forms for SANS and USANS analysis are:

• Beaucage.ipf -NEW- - Program incorporates the empirical multiple level unified Exponential/Power-law fit method developed by G. Beaucage. Four functions are included so that One, Two, Three, or Four levels can be used.
• BE.ipf - calculates the scattering function for polyelectrolyte solutions using the RPA expression of Borue and Erukhimovich.
• BimodalSchulzSpheres.ipf -NEW- - Calculates the scattering for a bidisperse population of spheres with uniform scattering length density. Each population of spheres is polydisperse with a distribution of radii obeying a Schulz distribution.
• BinaryHardSpheres.ipf -NEW- - This function calculates the scattered intensity for a binary mixture of spheres, including hard sphere interactions between the particles. Both of the populations are monodisperse. The calculation is an exact, multicomponent solution, using the Percus-Yevick closure. The three partial structure factors can also be calculated through a separate macro.
• CoreShell.ipf - Calculates the form factor, P(q), for a monodisperse spherical particle with a core-shell structure.
• CoreShellCylinder.ipf - Calculates the form factor for a monodisperse, right circular cylinder with a core-shell scattering length density profile. The shell thickness, t, is considered to be uniform over the entire surface of the core.
• CoreShell_and_Struct.ipf -NEW-
• CylinderForm.ipf - Calculates the form factor for a monodisperse right circular cylinder with uniform scattering length density.
• Cylinder_and_Struct.ipf -NEW-
• Cylinder_PolyLength.ipf -NEW- - Calculates the form factor for a polydisperse right circular cylinder with uniform scattering length density. A Schulz polydispersity of the cylinder length is considered.
• Cylinder_PolyRadius.ipf -NEW- - Calculates the form factor for a polydisperse right circular cylinder with uniform scattering length density. A Schulz polydispersity of the cylinder radius is considered.
• DAB_Model.ipf - calculates scattering from a randomly distributed two-phase system based on the Debye-Anderson-Brumberger model.
• Debye.ipf -NEW- - Calculates the Debye function, D(x), where D(x) represents the form factor for a linear polymer chain in the melt or in dilute solution (theta solvent).
• EllipticalCylinder.ipf -NEW- - Calculates the form factor for a cylinder with uniform scattering length density and an elliptical cross section.
• FlexCyl_EllipCross.ipf -NEW- - Calculates the form factor for a flexible cylinder with an elliptical cross section and a uniform scattering length density. The non-negligible diameter of the cylinder is included by accounting for excluded volume interactions within the walk of a single cylinder.
• FlexCyl_PolyLen.ipf -NEW- - Calculates the form factor for a flexible cylinder with a circular cross section and a uniform scattering length density. Polydispersity of the overall contour length is included, using a Schulz distribution. The non-negligible diameter of the cylinder is included by accounting for excluded volume interactions within the walk of a single cylinder.
• FlexCyl_PolyRadius.ipf -NEW- - Calculates the form factor for a flexible cylinder with a circular cross section and a uniform scattering length density. Polydispersity of the cross-section is included, using a Schulz distribution. The non-negligible diameter of the cylinder is included by accounting for excluded volume interactions within the walk of a single cylinder.
• FlexibleCylinder.ipf -NEW- - Calculates the form factor for a flexible cylinder with a circular cross section and a uniform scattering length density. The non-negligible diameter of the cylinder is included by accounting for excluded volume interactions within the walk of a single cylinder.
• Fractal.ipf -NEW- - Calculates the scattering from fractal-like aggregates built from spherical building blocks following the Texiera reference.
• GaussSpheres.ipf -NEW- - Calculates the scattering for a polydisperse population of spheres with uniform scattering length density. The distribution of radii is a Gaussian (normal) distribution.
• GaussSpheres_and_Struct.ipf -NEW-
• HardSphereStruct.ipf - Calculates the interparticle structure factor for monodisperse spherical particles interacting through hard sphere (excluded volume) interations. The solution uses the Percus-Yevick closure.
• HollowCylinders.ipf - Calculates the form factor for a monodisperse, hollow, right circular cylinder (or a tube). The inside and outside of the tube have the same scattering length density and the tube itself is of uniform SLD.
• HPMSA.ipf - This is the Hayter-Penfold/MSA solution for the structure factor for charged macroions in a dielectric medium. This structure factor can be combined with an appropriate form factor model.
• LamellarFF.ipf -NEW- - Calculates the form factor from a lyotropic lamellar phase. The intensity calculated is for lamellae of uniform scattering length density that are randomly distributed in solution (a powder average). The thickness of the lamellae is polydisperse. No inter-lamellar structure factor is calculated.
• LamellarFF_HG.ipf -NEW- - Calculates the form factor from a lyotropic lamellar phase. The intensity calculated is for lamellae of two-layer scattering length density that are randomly distributed in solution (a powder average). The scattering length density of the tail region,headgroup region, and solvent are taken to be different. No inter-lamellar structure factor is calculated.
• LamellarPS.ipf -NEW- - Calculates the scattered intensity from a lyotropic lamellar phase. The intensity (form factor and structure factor) calculated is for lamellae of uniform scattering length density that are randomly distributed in solution (a powder average). The lamellae thickness is polydiperse. The model can also be applied to large, multi-lamellar vesicles (MLV's). The instrumental resolution is convoluted into the structure factor only.
• LamellarPS_HG.ipf -NEW- - Calculates the scattered intensity from a lyotropic lamellar phase. The intensity calculated is for lamellae of two-layer scattering length density that are randomly distributed in solution (a powder average). The scattering length density of the tail region, headgroup region, and solvent are taken to be different. The model can also be applied to large, multi-lamellar vesicles (MLV's). The instrumental resolution is convoluted into the structure factor only.
• LogNormalSphere.ipf -NEW- - Calculates the scattering for a polydisperse population of spheres with uniform scattering length density. The distribution of radii is a LogNormal distribution.
• LogNormSpheres_and_Struct.ipf -NEW- -
• Lorentz_model.ipf - Model describes a Lorentzian (Ornstein-Zernicke) function including a flat background.
• MultiShell.ipf -NEW- - Calculates the form factor for monodisperse spherical particles made up of a solvent-filled core with N shells. The shells are interleaved with layers of solvent. For N=1, this is a model for a unilamellar vesicle, i.e. solvent core plus one shell (representing, e.g. a lipid bilayer), and surrounded by solvent. N > 1 corresponds to a multilamellar vesicle.
• OblateCS_and_Struct.ipf -NEW- -
• OblateForm.ipf - Calculates the form factor for an oblate ellipsoid particle with a core/shell structure.PolyCore.ipf - Calculates the form factor for polydispersed spherical particles with a core-shell structure. The spherical particles have a polydisperse core with a constant shell thickness.
• Parallelepiped.ipf -NEW- - Calculates the form factor for a rectangular solid with uniform scattering length density.
• Peak_Gauss_Model.ipf - Model describes a Gaussian shaped peak including a flat background.
• Peak_Lorentz_Model.ipf - Model describes a Lorentzian shaped peak including a flat background.
• PolyCore.ipf - Calculates the form factor for polydispersed spherical particles with a core-shell structure. The spherical particles have a polydisperse core with a constant shell thickness.
• PolyCoreShellCylinder.ipf -NEW- - This function calculates the scattering for a polydisperse, right circular cylinder with a core-shell scattering length density profile. The shell thickness on the flat ends of the cylinder is independent of the shell thickness on the radial surface. Polydispersity of the cylinder core radius is modelled using a log-normal distribution. The overall intensity is obtained by calculating the scattering from each particle size present and weighting it by the normalised distribution.
• PolyCoreShellRatio.ipf - Calculates the form factor for a polydisperse spherical particle with a core-shell structure. In this model, the ratio R(core)/R(core+shell) is held constant.
• PolyCore_and_Struct.ipf -NEW-
• PolyCSRatio_and_Struct.ipf -NEW-
• PolyHardSphereInten.ipf - This function calculates the scattered intensity for a population of polydisperse spheres, including hard sphere interactions between the particles. The calculation is an exact, multicomponent solution, using the Percus-Yevick closure. A Schulz distribution is used to describe the polydispersity of the diameter.
• PolyRectSphere_and_Struct.ipf -NEW-
• Power_Law_Model.ipf - Model describes a general power-law decay including a flat background.
• ProlateCS_and_Struct.ipf -NEW-
• ProlateForm.ipf - Calculates the form factor for a monodisperse prolate ellipsoid particle with a core/shell structure.
• RectPolySpheres.ipf - Calculates the form factor for a polydisperse population of spheres with uniform scattering length density. The distribution of radii is a rectangular (box) distribution.
• SchulzSpheres.ipf -NEW- - Calculates the scattering for a polydisperse population of spheres with uniform scattering length density. The distribution of radii is a Schulz distribution.
• SchulzSpheres_and_Struct.ipf -NEW-
• SmearedRPA.ipf - Calculates the macroscopic scattering intensity (units of cm^-1) for a multicomponent homogeneous mixture of polymers using the Random Phase Approximation. This general formalism contains 10 specific cases.
• Sphere.ipf - Calculates the form factor, P(q), for a monodisperse spherical particle with uniform scattering length density.
• Sphere_and_Struct.ipf -NEW-
• SquareWellStruct.ipf - Calculates the interparticle structure factor for a square well fluid of spherical particles. Uses the MSA closure, and has limited applicability.
• StackDisks.ipf - Calculates the total coherent scattered intensity from stacked discs (tactoids) with a core/layer structure. Assuming the next neighbor distance (d-spacing) in a stack of parallel discs obeys a Gaussian distribution, a structure factor S(q) proposed by Kratky and Porod in 1949 is used in this function.
• StickyHardSphereStruct.ipf -NEW- - Calculates the interparticle structure factor for a hard sphere fluid with a narrow attractive well. A perturbative solution of the Percus-Yevick closure is used. The strength of the attractive well is described in terms of "stickiness".
• Teubner.ipf - This function calculates the scattered intensity of a two-component system using the Teubner-Strey model.
• TriaxialEllipsoid.ipf -NEW- - Calculates the form factor for a triaxial ellipsoid with uniform scattering length density.
• UnifEllipsoid_and_Struct.ipf -NEW-
• Uniform ellipsoid.ipf - Calculates the form factor for a monodisperse ellipsoid (ellipsoid of revolution) with uniform scattering length density.
• Vesicle_UL.ipf -NEW- - Calculates the form factor, P(q), for a monodisperse, unilamellar vesicle. The form factor is normalized by the volume of the shell, rather than the total particle volume.
• Vesicle_UL_and_Struct.ipf -NEW-

Last modified 18-August-2006