Adding comments and modifying properties in the PW module (deepmodeling#4405)

* 对于'source/module_relax/relax_old' 的第85行附近进行了
修改

* A.s

* class change

* xiugai

* add some comments

---------

Co-authored-by: DoctorDra <DoctorDra@https://github.com>
Co-authored-by: Mohan Chen <mohan.chen.chen.mohan@gmail.com>

Author: 3 people

source/module_basis/module_pw/fft.h

@@ -84,11 +84,12 @@ class FFT
 #endif // defined(__ENABLE_FLOAT_FFTW)
 	// void initplanf_mpi();
 
-public:
+private:
 	int fftnx=0, fftny=0;
 	int fftnxy=0;
 	int ny=0, nx=0, nz=0;
 	int nxy=0;
+public :
 	bool xprime = true; // true: when do recip2real, x-fft will be done last and when doing real2recip, x-fft will be done first; false: y-fft
                          // For gamma_only, true: we use half x; false: we use half y
 	int lixy=0,rixy=0;// lixy: the left edge of the pw ball in the y direction; rixy: the right edge of the pw ball in the x or y direction
@@ -110,8 +111,8 @@ class FFT
   private:
     bool gamma_only = false;
     bool mpifft = false; // if use mpi fft, only used when define __FFTW3_MPI
-
-    fftw_plan planzfor  = NULL;
+//add by A.s 202406 considering that no all people are familiar with fftw3,some comments should be added.
+    fftw_plan planzfor  = NULL;//create a special pointer pointing to the fftw_plan class as a plan for performing FFT
     fftw_plan planzbac  = NULL;
 	fftw_plan planxfor1 = NULL;
 	fftw_plan planxbac1 = NULL;

source/module_basis/module_pw/pw_basis.cpp

@@ -146,9 +146,10 @@ void PW_Basis::collect_uniqgg()
     if(this->npw <= 0) return;
     this->ig_gge0 = -1;
     delete[] this->ig2igg; this->ig2igg = new int [this->npw];
-    int *sortindex = new int [this->npw];
-    double *tmpgg = new double [this->npw];
-    double *tmpgg2 = new double [this->npw];
+//add by A.s 202406
+    int *sortindex = new int [this->npw];//Reconstruct the mapping of the plane wave index ig according to the energy size of the plane waves
+    double *tmpgg = new double [this->npw];//Ranking the plane waves by energy size while ensuring that the same energy is preserved for each wave to correspond
+    double *tmpgg2 = new double [this->npw];//ranking the plane waves by energy size and removing the duplicates
     ModuleBase::Vector3<double> f;
     for(int ig = 0 ; ig < this-> npw ; ++ig)
     {
@@ -175,8 +176,8 @@ void PW_Basis::collect_uniqgg()
     int igg = 0;
     this->ig2igg[sortindex[0]] = 0;
     tmpgg2[0] = tmpgg[0];
-    double avg_gg = tmpgg2[igg];
-    int avg_n = 1;
+    double avg_gg = tmpgg2[igg];//For waves with similar energy,take the average
+    int avg_n = 1;//The number of waves required to take the average
     for (int ig = 1; ig < this->npw; ++ig)
     {
         if (std::abs(tmpgg[ig] - tmpgg2[igg]) > 1.0e-8)
@@ -233,4 +234,4 @@ void PW_Basis::set_precision(std::string precision_) {
     this->precision = std::move(precision_);
 }
 
-}
+}

source/module_relax/relax_old/lattice_change_cg.cpp

@@ -85,6 +85,7 @@ void Lattice_Change_CG::start(UnitCell &ucell, const ModuleBase::matrix &stress_
     double *cg_gradn = new double[dim];
     double *move = new double[dim];
     double *cg_grad = new double[dim];
+
     double best_x = 0.0;
     double fmin = 0.0;