namespace gpr::potentials

Overview

namespace potentials {
 
// global variables
 
double MULLER_BROWN_MINIMA[3][2] = {     {-0.558224, 1.441726},     {0.623499, 0.028038},     {-0.050011, 0.466694}, };
double MULLER_BROWN_SADDLES[2][2] = {     {-0.822002, 0.624313},     {0.212487, 0.292988}, };
double LEPS_REACTANT[2] = {0.742, 4.0};
double LEPS_PRODUCT[2] = {4.0, 0.742};
double LEPS_SADDLE[2] = {0.929, 0.929};
 
// global functions
 
std::pair<double, std::vector<double>> lj_energy_gradient(const std::vector<double>& x, double epsilon = 1.0, double sigma = 1.0);
std::pair<double, std::vector<double>> muller_brown_energy_gradient(const std::vector<double>& xy);
std::pair<double, std::vector<double>> leps_energy_gradient(const std::vector<double>& r);
 
} // namespace potentials

Detailed Documentation

Global Functions

std::pair<double, std::vector<double>> lj_energy_gradient(const std::vector<double>& x, double epsilon = 1.0, double sigma = 1.0)

Lennard-Jones energy and gradient for N atoms in 3D.

Parameters:

x	Flat coordinate vector [x1,y1,z1,x2,y2,z2,…], size 3*N
epsilon	LJ well depth
sigma	LJ zero-crossing distance

Returns:

(energy, gradient) pair

std::pair<double, std::vector<double>> muller_brown_energy_gradient(const std::vector<double>& xy)

Muller-Brown 2D potential.

Three minima and two saddle points on a 2D surface. Classic benchmark for NEB and dimer methods.

Parameters:

xy	2-element vector [x, y]

Returns:

(energy, gradient) pair

std::pair<double, std::vector<double>> leps_energy_gradient(const std::vector<double>& r)

LEPS (London-Eyring-Polanyi-Sato) potential for collinear A+BC.

2D potential in (r_AB, r_BC) coordinates for the collinear reaction A + BC -> AB + C. Classic benchmark for NEB and dimer methods.

Parameters:

r	2-element vector [r_AB, r_BC]

Returns:

(energy, gradient) pair