Scattering
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class Scattering : public feasst::Analyze
Compute the scattering intensity.
\(F(\vec{q}) = \sum f_i(|\vec{q}|R_i) \exp(-i \vec{q} \cdot \vec{r}_i)\)
where \(r\) is the position of site \(i\), \(q\) is the frequency and \(f_i\) are the scattering lengths, assumed to be spherical with a radius, \(R_i = \sigma_i\).
\(f(qR) = 3 V(R) \frac{\sin(qR)-qR\cos(qr)}{q^3R^3}\),
\(V(R)=\frac{4}{3}\pi R^3\).
The intensity, \(I\), is then given by the \(F(\vec{q})\) multiplied by its complex conjugate:
\(I(q) = |F(\vec{q})|^2\).
Public Functions
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void initialize(Criteria *criteria, System *system, TrialFactory *trial_factory)
Initialize and precompute before trials.
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void update(const Criteria &criteria, const System &system, const TrialFactory &trial_factory)
Perform update action.
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std::string write(const Criteria &criteria, const System &system, const TrialFactory &trial_factory)
Perform write action.
Arguments
num_frequency: the number of linearly spaced frequencies between the largest and the smallest, 2*pi/minimum_domain_length (default: 100).
Stepper arguments.
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void initialize(Criteria *criteria, System *system, TrialFactory *trial_factory)