NXCalculator

This is a tool for calculating some basic characteristics for neutron and X-ray scattering. Given an input chemical formula, we will be calculating several critical quantities for your sample.

The quantities to be calculated will be useful for post-processing your total scattering data and they include the Faber-Ziman coefficient, self-scattering level, scattering weight of partials, and potentially, a suggested input packing fraction.

If provided mass density and radius of sample, we can also calculate the neutron resonance.

Concerning the sample mass density, either you can directly input the value in 'Sample Mass Density' box down below, or you can fill in the mass and height information so we can calculate the density for you.

Composition: Show/hide notes (Required sample chemical formula in a certain form, e.g., Sr1 Ti1 O3, or Sr Ti O3, or Sr1 Ti (16O)3, where '(16O)' specifies a certain isotope)

Sample (i.e., Powder) Mass Density (g/cm^3, optional): Show/hide notes (N.B. This is the measured mass density of your powder sample. As we need it for absorption spectrum calculation, it will be defaulted to 1.0, if not provided.)

Mass Sample & Containter (g, optional): Show/hide notes (N.B. The value here and the three following ones can be used for figuring out the mass density. If the density is given above, relevant input boxes will be greyed out.)

Mass Container Only (g, optional):

Container Inner Radius (cm, optional): Show/hide notes (N.B. The value here can be used for the absorption spectrum calculation. Default: 0.3)

Sample Height (cm, optional):

Full Number Density (angstrom^-3, optional): Show/hide notes (N.B. This is the crystallographic number density. If you have a CIF file, you can obtain the full number density here)

Data Level at High Q (optional): Show/hide notes (N.B. This is actual asymptotic level at high Q in your reduced normalized S(Q) data, which should asymptotically approach 1 at high Q)

Scattering Angles (degree, optional): Show/hide notes (Central scattering angle for physical banks, e.g., '15, 66, 90, 155', or '16 66 90 155')

Information

*Data for neutron calculations were taken from the following resource, V. F. Sears, Neutron News, 3, 3, 1992, 26-37, consistent with the NIST table.

*Data for X-ray calculations were taken from the following resource, D. Waasmaier and A. Kirfel, Acta Cryst., A51, 1995, 416-431.

*A proper input of sample chemical formula is for sure required.

*Default values have been given to those variables needed for resonance absorption calculation.

*Given the input chemical formula and the measured mass density, the corresponding number density can be calculated.

*Given the full number density input, the full mass density can be calculated. But one needs to input a valid value in the 'Data Level at High Q' box, since the suggested packing fraction will be calculated altogether.