class LennardJonesCutShift : public feasst::LennardJonesAlpha

The Lennard-Jones potential, \(U_{LJ}\) is described in LennardJones. This class implements the cut and shifted (CS) version which ensures \(U(r_c)=0\).

\( U_{LJ}^{CS}(r) = \left\{ \begin{array}{lr} U_{LJ}(r) - U_{LJ}(r_c) & : r < r_c \\ 0 & r \ge r_c \end{array} \right. \)

For a Weeks-Chandler-Anderson (WCA) potential, use this class. The cutoffs are computed by LennardJonesCutShift::set_wca. Thus, one workflow is as follows:

ModelParams wca_params = configuration.model_params(); // copy model params LennardJonesCutShift::set_wca(type1, type2, wca_params); // set cutoff wca->precompute(wca_params); // compute shifts, etc Potential::set_model_params(wca_params); // use wca_params.

Public Functions

void precompute(const ModelParams &existing)

Precompute the shift factor for optimization, given existing model parameters.

void set_alpha(const double alpha)

Set the value of \(\alpha\). The default value is 6.

void set_wca(const int site_type1, const int site_type2, ModelParams *params)

Initialize WCA cutoff distances for types 1 and 2 in model parameters.

void serialize(std::ostream &ostr) const

Output a serialized version of the existing model.