#ifndef PERTURBED_H_
#define PERTURBED_H_

/** \file perturbed.h
 * Header file for \ref perturbed.c
 * 
 * Contains declarations of the functions implemented in \ref perturbed.c
 * 
  Project: ParallelCarParrinello
 \author Frederik Heber
 \date 2006

*/


void MinimisePerturbed (struct Problem *P, int *Stop, int *SuperStop);
void InitPerturbedEnergyCalculation(struct Problem *P, const int first);
void UpdatePerturbedEnergyCalculation(struct Problem *P);
void CalculatePerturbedEnergy(struct Problem *P, const int l, const int DoGradient, const int first);
void CalculatePerturbationOperator_PxR(struct Problem *P, const fftw_complex *source, fftw_complex *dest, const int l, const int index_pxr);
void CalculatePerturbationOperator_RxP(struct Problem *P, const fftw_complex *source, fftw_complex *dest, const int l, const int index_rxp);
void CalculatePerturbationOperator_R(struct Problem *P, const fftw_complex *source, fftw_complex *dest, const fftw_complex *source2, const int index_r, const int wavenr);
void CalculatePerturbationOperator_P(struct Problem *P, const fftw_complex *source, fftw_complex *dest, const int index_g);
void FillCurrentDensity(struct Problem *P);
void FillDeltaCurrentDensity(struct Problem *P);
double Calculate1stPerturbedDerivative(struct Problem *P, const fftw_complex *source0, const fftw_complex *source, const fftw_complex *ConDir, const fftw_complex *Hc_grad, const fftw_complex *H1c_grad);
double Calculate2ndPerturbedDerivative(struct Problem *P, const fftw_complex *source0, const fftw_complex *source, const fftw_complex *ConDir, const double sourceHsource, const double ConDirHConDir, const double ConDirConDir);
void FindPerturbedMinimum(struct Problem *P);
void CalculateOverlap(struct Problem *P, const int l, const enum PsiTypeTag state); 
int CheckOrbitalOverlap(struct Problem *P);
void ApplyTotalHamiltonian(struct Problem *P, const fftw_complex *source, fftw_complex *dest, fftw_complex ***fnl, const double PsiFactor, const int first);
void CalculateMagneticSusceptibility (struct Problem *P);
void CalculateMagneticMoment(struct Problem *P);
void CalculateChemicalShieldingByReciprocalCurrentDensity(struct Problem *P);
void CalculateChemicalShieldingbyDESolver(struct Problem *P);
void OutputOrbitalPositions(struct Problem *P, const enum PsiTypeTag type);
void fft_Psi(struct Problem *P, const fftw_complex *Psi, fftw_real *PsiR, const int index, const int symmetry);
inline int cross(const int i, const int j);
inline int crossed(int i, int j);
void AllocCurrentDensity(struct Density *Dens0);
void DisAllocCurrentDensity(struct Density *Dens0);
void PlotVectorPlane(struct Problem *P, int B_Index, int n_orth);
void ReadSrcPerturbedPsis(struct Problem *P, enum PsiTypeTag type);
inline double ShiftGaugeOrigin(struct Problem *P, double r[NDIM], const int index);
inline double sawtooth(struct Lattice *Lat, double L[NDIM], const int index);
inline void MinImageConv(struct Lattice *Lat, const double R[NDIM], const double r[NDIM], double *result);
void test_fft_symmetry(struct Problem *P, const int l);
void test_rxp(struct Problem *P);
void TestSawtooth(struct Problem *P, const int index);
void TestCurrent(struct Problem *P, const int index);
void TestReciprocalCurrent(struct Problem *P, const fftw_complex *currentC, struct OneGData *GArray, int in);

#endif /*PERTURBED_H_*/