SLD Calculator Tool

Description

The neutron scattering length density (SLD, \(\beta_N\)) is defined as

\[\beta_N = (b_{c1} + b_{c2} + ... + b_{cn}) / V_m\]

where \(b_{ci}\) is the bound coherent scattering length of ith of n atoms in a molecule with the molecular volume \(V_m\).

To calculate scattering length densities enter the empirical formula of a compound and its mass density and click “Calculate”.

Entering a wavelength value is optional (a default value of 6.0 Å will be used).

TIPS!

Formula strings consist of atoms and the number of them, such as “CaCO3+6H2O”.
Groups can be separated by ‘+’ or space, so “CaCO3 6H2O” works as well.
Groups can be defined using parentheses, such as “CaCO3(H2O)6”.
Parentheses can be nested, such as “(CaCO3(H2O)6)1”.
Isotopes are represented by their atomic number in square brackets, such as “CaCO[18]3+6H2O”, H[1], or H[2].
Numbers of atoms can be integer or decimal, such as “CaCO3+(3HO0.5)2”.
The SLD of mixtures can be calculated as well. For example, for a 70-30 mixture of H2O/D2O write “H14O7+D6O3” or more simply “H7D3O5” (i.e. this says 7 hydrogens, 3 deuteriums, and 5 oxygens) and enter a mass density calculated on the percentages of H2O and D2O.
Type “C[13]6 H[2]12 O[18]6” for C(13)6H(2)12O(18)6 (6 Carbon-13 atoms, 12 deuterium atoms, and 6 Oxygen-18 atoms).

Note

This help document was last changed by Paul Kienzle, 05Apr2017