From 686f973d35ed68d9975667941e0a8899a81727bb Mon Sep 17 00:00:00 2001
From: Jean-Luc Fattebert <fattebertj@ornl.gov>
Date: Sat, 1 Mar 2025 22:05:57 -0500
Subject: [PATCH] More clean up in class Potentials

* remove some unused functions
* make use of class MGmol_MPI
* change some function names for clarity
* fix some minor bug in iterative indexes
---
 src/MGmol.cc      |  9 +++---
 src/Potentials.cc | 70 ++++++++++++++---------------------------------
 src/Potentials.h  | 15 +++-------
 3 files changed, 29 insertions(+), 65 deletions(-)

diff --git a/src/MGmol.cc b/src/MGmol.cc
index 8d87f1c1..c18e58c7 100644
--- a/src/MGmol.cc
+++ b/src/MGmol.cc
@@ -400,7 +400,6 @@ int MGmol<OrbitalsType>::initial()
     current_orbitals_->setDataWithGhosts();
     current_orbitals_->trade_boundaries();
 
-    //    if(ct.restart_info <= 1)pot.initWithVnuc();
     // initialize matrices S and invB
 
     if (ct.numst > 0)
@@ -1379,14 +1378,14 @@ void MGmol<OrbitalsType>::update_pot(const Ions& ions)
 
     const bool flag_mixing = (fabs(ct.mix_pot - 1.) > 1.e-3);
 
-    // evaluate potential correction
+    // update total potential
     if (flag_mixing)
     {
-        pot.delta_v(rho_->rho_);
-        pot.update(ct.mix_pot);
+        pot.computeDeltaV(rho_->rho_);
+        pot.updateVtot(ct.mix_pot);
     }
     else
-        pot.update(rho_->rho_);
+        pot.updateVtot(rho_->rho_);
 }
 
 template <class OrbitalsType>
diff --git a/src/Potentials.cc b/src/Potentials.cc
index 96375c6d..4da9ab9a 100644
--- a/src/Potentials.cc
+++ b/src/Potentials.cc
@@ -87,37 +87,19 @@ Potentials::Potentials()
 #endif
 }
 
-void Potentials::initWithVnuc()
-{
-    assert(size_ > 0);
-    if (verbosity_level_ > 2 && onpe0)
-        (*MPIdata::sout) << "Potentials::initWithVnuc()" << std::endl;
-    itindex_vxc_ = 0;
-    itindex_vh_  = 0;
-    int ione     = 1;
-    Tcopy(&size_, &v_nuc_[0], &ione, &vtot_[0], &ione);
-    double one = 1.;
-    LinearAlgebraUtils<MemorySpace::Host>::MPaxpy(
-        size_, one, &v_ext_[0], &vtot_[0]);
-    // factor ha2ry to get total potential in [Ry] for calculations
-    LinearAlgebraUtils<MemorySpace::Host>::MPscal(size_, ha2ry, &vtot_[0]);
-}
-
 double Potentials::max() const
 {
-    Mesh* mymesh             = Mesh::instance();
-    const pb::PEenv& myPEenv = mymesh->peenv();
-    double vmax              = (*max_element(vtot_.begin(), vtot_.end()));
-    vmax                     = myPEenv.double_max_all(vmax);
+    MGmol_MPI& mmpi = *(MGmol_MPI::instance());
+    double vmax     = (*max_element(vtot_.begin(), vtot_.end()));
+    vmax            = mmpi.allreduce(&vmax, 1, MPI_MAX);
     return vmax;
 }
 
 double Potentials::min() const
 {
-    Mesh* mymesh             = Mesh::instance();
-    const pb::PEenv& myPEenv = mymesh->peenv();
-    double vmin              = -(*min_element(vtot_.begin(), vtot_.end()));
-    vmin                     = -myPEenv.double_max_all(vmin);
+    MGmol_MPI& mmpi = *(MGmol_MPI::instance());
+    double vmin     = -(*min_element(vtot_.begin(), vtot_.end()));
+    vmin            = -mmpi.allreduce(&vmin, 1, MPI_MAX);
     return vmin;
 }
 
@@ -141,7 +123,7 @@ void Potentials::evalNormDeltaVtotRho(
     mmpi.allreduce(&scf_dvrho_, 1, MPI_SUM);
 }
 
-double Potentials::update(const std::vector<std::vector<RHODTYPE>>& rho)
+double Potentials::updateVtot(const std::vector<std::vector<RHODTYPE>>& rho)
 {
     assert(itindex_vxc_ >= 0);
     assert(itindex_vh_ >= 0);
@@ -149,9 +131,8 @@ double Potentials::update(const std::vector<std::vector<RHODTYPE>>& rho)
 
     if (verbosity_level_ > 2 && onpe0)
         (*MPIdata::sout) << "Potentials::update(rho)" << std::endl;
-    int ione                 = 1;
-    Mesh* mymesh             = Mesh::instance();
-    const pb::PEenv& myPEenv = mymesh->peenv();
+    int ione        = 1;
+    MGmol_MPI& mmpi = *(MGmol_MPI::instance());
 
     // save old potentials
     Tcopy(&size_, &vtot_[0], &ione, &vtot_old_[0], &ione);
@@ -181,23 +162,22 @@ double Potentials::update(const std::vector<std::vector<RHODTYPE>>& rho)
         = LinearAlgebraUtils<MemorySpace::Host>::MPdot(size_, &dv_[0], &dv_[0]);
 
     double sum = 0.;
-    int rc
-        = MPI_Allreduce(&dvdot, &sum, 1, MPI_DOUBLE, MPI_SUM, myPEenv.comm());
+    int rc     = mmpi.allreduce(&dvdot, &sum, 1, MPI_SUM);
     if (rc != MPI_SUCCESS)
     {
         std::cerr << "MPI_Allreduce double sum failed!!!" << std::endl;
-        MPI_Abort(myPEenv.comm(), EXIT_FAILURE);
+        mmpi.abort();
     }
     dvdot = sum;
 
     scf_dv_            = 0.5 * sqrt(dvdot);
-    const double gsize = (double)size_ * (double)myPEenv.n_mpi_tasks();
+    const double gsize = (double)size_ * (double)mmpi.size();
     scf_dv_ /= gsize;
 
     return scf_dv_;
 }
 
-void Potentials::update(const double mix)
+void Potentials::updateVtot(const double mix)
 {
     assert(itindex_vxc_ == itindex_vh_);
 
@@ -210,7 +190,7 @@ void Potentials::update(const double mix)
         size_, potmix, &dv_[0], &vtot_[0]);
 }
 
-double Potentials::delta_v(const std::vector<std::vector<RHODTYPE>>& rho)
+double Potentials::computeDeltaV(const std::vector<std::vector<RHODTYPE>>& rho)
 {
     assert(itindex_vxc_ == itindex_vh_);
     assert(size_ > 0);
@@ -218,9 +198,8 @@ double Potentials::delta_v(const std::vector<std::vector<RHODTYPE>>& rho)
     if (verbosity_level_ > 2 && onpe0)
         (*MPIdata::sout) << "Potentials::delta_v()" << std::endl;
 
-    int ione                 = 1;
-    Mesh* mymesh             = Mesh::instance();
-    const pb::PEenv& myPEenv = mymesh->peenv();
+    int ione        = 1;
+    MGmol_MPI& mmpi = *(MGmol_MPI::instance());
 
     // save old potentials
     Tcopy(&size_, &vtot_[0], &ione, &vtot_old_[0], &ione);
@@ -249,17 +228,16 @@ double Potentials::delta_v(const std::vector<std::vector<RHODTYPE>>& rho)
         = LinearAlgebraUtils<MemorySpace::Host>::MPdot(size_, &dv_[0], &dv_[0]);
 
     double sum = 0.;
-    int rc
-        = MPI_Allreduce(&dvdot, &sum, 1, MPI_DOUBLE, MPI_SUM, myPEenv.comm());
+    int rc     = mmpi.allreduce(&dvdot, &sum, 1, MPI_SUM);
     if (rc != MPI_SUCCESS)
     {
         std::cerr << "MPI_Allreduce double sum failed!!!" << std::endl;
-        MPI_Abort(myPEenv.comm(), EXIT_FAILURE);
+        mmpi.abort();
     }
     dvdot = sum;
 
     scf_dv_            = 0.5 * sqrt(dvdot);
-    const double gsize = (double)size_ * (double)myPEenv.n_mpi_tasks();
+    const double gsize = (double)size_ * (double)mmpi.size();
     scf_dv_ /= gsize;
 
     return scf_dv_;
@@ -437,7 +415,6 @@ void Potentials::readExternalPot(const std::string filename, const char type)
                 {
                     assert(index < size_);
                     (*from) >> v_ext_[index];
-                    //(*MPIdata::sout)<<myPEenv.mytask();
                     //(*MPIdata::sout)<<",
                     // v_ext_["<<index<<"]="<<v_ext_[index]<<endl;
                     index++;
@@ -568,6 +545,7 @@ void Potentials::readAll(std::vector<Species>& sp)
         isp++;
     }
 }
+
 template <typename T>
 void Potentials::setVxc(const T* const vxc, const int iterativeIndex)
 {
@@ -576,13 +554,6 @@ void Potentials::setVxc(const T* const vxc, const int iterativeIndex)
     itindex_vxc_ = iterativeIndex;
     MPcpy(&vxc_rho_[0], vxc, size_);
 }
-void Potentials::setVh(const POTDTYPE* const vh, const int iterativeIndex)
-{
-    assert(iterativeIndex >= 0);
-    int ione    = 1;
-    itindex_vh_ = iterativeIndex;
-    Tcopy(&size_, vh, &ione, &vh_rho_[0], &ione);
-}
 
 void Potentials::setVh(
     const pb::GridFunc<POTDTYPE>& vh, const int iterativeIndex)
@@ -932,6 +903,7 @@ int Potentials::read(HDFrestart& h5f_file)
 
     // Read the hartree potential
     h5f_file.read_1func_hdf5(vh_rho_.data(), "Hartree");
+    itindex_vh_ = 0;
 
     // Read dielectric potential
     if (ct.diel)
diff --git a/src/Potentials.h b/src/Potentials.h
index 8e9b763c..c7062234 100644
--- a/src/Potentials.h
+++ b/src/Potentials.h
@@ -26,7 +26,6 @@ class GridFunc;
 
 class Potentials
 {
-
     int size_;
     int gdim_[3];
     int dim_[3];
@@ -167,28 +166,23 @@ class Potentials
 
     double getChargeInCell() const { return charge_in_cell_; }
 
-    /*!
-     * initialize total potential as local pseudopotential
-     */
-    void initWithVnuc();
-
     void getVofRho(std::vector<POTDTYPE>& vrho) const;
 
     /*!
      * evaluate potential correction associated with a new rho
      */
-    double delta_v(const std::vector<std::vector<RHODTYPE>>& rho);
+    double computeDeltaV(const std::vector<std::vector<RHODTYPE>>& rho);
 
     /*!
-     * update potentials based on argument rho
+     * update total potential with updated components
      */
-    double update(const std::vector<std::vector<RHODTYPE>>& rho);
+    double updateVtot(const std::vector<std::vector<RHODTYPE>>& rho);
 
     /*!
      * update potentials based on potential correction delta v and mixing
      * parameter
      */
-    void update(const double mix);
+    void updateVtot(const double mix);
 
     double max() const;
     double min() const;
@@ -196,7 +190,6 @@ class Potentials
 
     template <typename T>
     void setVxc(const T* const vxc, const int iterativeIndex);
-    void setVh(const POTDTYPE* const vh, const int iterativeIndex);
     void setVh(const pb::GridFunc<POTDTYPE>& vh, const int iterativeIndex);
 
     void initialize(Ions& ions);