soft_core_potentials.h

// -*-c++-*-
#ifndef STORMM_SOFT_CORE_POTENTIALS_H
#define STORMM_SOFT_CORE_POTENTIALS_H
 
#include <cmath>
#include "copyright.h"
#include "Accelerator/hybrid.h"
#include "Constants/scaling.h"
#include "DataTypes/common_types.h"
#include "Math/matrix_ops.h"
#include "Parsing/parse.h"
#include "Parsing/polynumeric.h"
#include "energy_enumerators.h"
 
namespace stormm {
namespace energy {
 
using card::Hybrid;
using parse::NumberFormat;
using parse::realToString;
using stmath::invertSquareMatrix;
using stmath::matrixVectorMultiply;
using stmath::qrSolver;

constexpr int max_quartic_spline_count = 64;

template <typename Tcalc>
void linearCoreElectrostatics(const Tcalc r, const Tcalc clash_distance, const Tcalc qiqj,
                              Tcalc *ele_contrib, Tcalc *fmag = nullptr);

template <typename Tcalc>
void quadraticCoreElectrostatics(const Tcalc r, const Tcalc clash_distance, const Tcalc qiqj,
                                 Tcalc *ele_contrib, Tcalc *fmag = nullptr);

template <typename Tcalc>
void cubicCoreElectrostatics(const Tcalc r, const Tcalc clash_distance, const Tcalc qiqj,
                             Tcalc *ele_contrib, Tcalc *fmag = nullptr);

template <typename Tcalc>
void cubicCoreLennardJones(const Tcalc r, const Tcalc clash_ratio, const Tcalc lja,
                           const Tcalc ljb, Tcalc *vdw_contrib, Tcalc *fmag = nullptr);
  
template <typename Tcalc>
void quarticCoreLennardJones(const Tcalc r, const Tcalc clash_ratio, const Tcalc lja,
                             const Tcalc ljb, Tcalc *vdw_contrib, Tcalc *fmag = nullptr);

void adjustIntervalTarget(std::vector<double> *interval_targets, int index, double f_rswitch,
                          double target_zero, double move_increment);

double evaluateQuarticFirstDerivative(const double4 coeffs, double r);

template <typename Tcalc4>
void cubicSoftCore(Tcalc4* abcd_coefficients, double rswitch, double f_rswitch, double df_rswitch,
                   double target_zero = 0.0);

template <typename Tcalc4, typename Tcalc>
void quarticSoftCore(Tcalc4* abcd_coefficients, Tcalc* e_coefficient, double rswitch,
                     double f_rswitch, double df_rswitch, double d2f_rswitch,
                     double target_zero = 0.0);

template <typename Tcalc4, typename Tcalc2>
void quinticSoftCore(Tcalc4* abcd_coefficients, Tcalc2* ef_coefficients, double rswitch,
                     double f_rswitch, double df_rswitch, double d2f_rswitch, double d3f_rswitch,
                     double target_zero = 0.0);

template <typename Tcalc4>
void exponentialSoftCore(Tcalc4 *abcd_coefficients, double v, double rswitch, double f_rswitch,
                         double df_rswitch, double d2f_rswitch, double d3f_rswitch);
 
} // namespace energy
} // namespace stormm
 
#include "soft_core_potentials.tpp"
 
#endif