[49148bb] | 1 | .. sld_calculator_help.rst |
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| 2 | |
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| 3 | .. This is a port of the original SasView html help file to ReSTructured text |
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| 4 | .. by S King, ISIS, during SasView CodeCamp-III in Feb 2015. |
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| 5 | |
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| 6 | SLD Calculator Tool |
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| 7 | =================== |
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| 8 | |
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| 9 | Description |
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| 10 | ----------- |
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| 11 | |
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| 12 | The neutron scattering length density (SLD) is defined as |
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| 13 | |
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| 14 | SLD = (b_c1 + b_c2 + ... + b_cn) / Vm |
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| 15 | |
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| 16 | where b_ci is the bound coherent scattering length of ith of n atoms in a molecule |
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| 17 | with the molecular volume Vm |
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| 18 | |
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| 19 | .. ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ |
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| 20 | |
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| 21 | Specifying the Compound Name |
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| 22 | ---------------------------- |
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| 23 | |
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| 24 | To calculate scattering length densities enter the empirical formula of a |
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| 25 | compound and its mass density and click "Calculate". |
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| 26 | |
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| 27 | Entering a wavelength value is optional (a default value of 6.0 |Ang| will |
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| 28 | be used). |
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| 29 | |
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| 30 | TIPS! |
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| 31 | |
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| 32 | * Formula strings consist of atoms and the number of them, such as "CaCO3+6H2O". |
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| 33 | |
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| 34 | * Groups can be separated by *'+'* or *space*, so "CaCO3 6H2O" works as well. |
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| 35 | |
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| 36 | * Groups can be defined using parentheses, such as "CaCO3(H2O)6". |
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| 37 | |
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| 38 | * Parentheses can be nested, such as "(CaCO3(H2O)6)1". |
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| 39 | |
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| 40 | * Isotopes are represented by their atomic number in *square brackets*, such |
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| 41 | as "CaCO[18]3+6H2O", H[1], or H[2]. |
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| 42 | |
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| 43 | * Numbers of atoms can be integer or decimal, such as "CaCO3+(3HO0.5)2". |
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| 44 | |
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| 45 | * The SLD of mixtures can be calculated as well. For example, for a 70-30 |
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| 46 | mixture of H2O/D2O write "H14O7+D6O3" or more simply "H7D3O5" (i.e. this says |
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| 47 | 7 hydrogens, 3 deuteriums, and 5 oxygens) and enter a mass density calculated |
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| 48 | on the percentages of H2O and D2O. |
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| 49 | |
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| 50 | * Type "C[13]6 H[2]12 O[18]6" for C(13)6H(2)12O(18)6 (6 Carbon-13 atoms, 12 |
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| 51 | deuterium atoms, and 6 Oxygen-18 atoms). |
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| 52 | |
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| 53 | .. ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ |
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| 54 | |
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| 55 | .. note:: This help document was last changed by Steve King, 01May2015 |
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| 56 | |
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