From 65ef3b21c411b31df7af008137b120a680f6dc9e Mon Sep 17 00:00:00 2001
From: eric bylaska <eric.bylaska@pnnl.gov>
Date: Wed, 9 Oct 2024 16:57:12 -0700
Subject: [PATCH] ...EJB

---
 Nwpw/pspw/minimizer/cgsd_bybminimize0.dev | 129 ++++++++++++++++++++++
 1 file changed, 129 insertions(+)
 create mode 100644 Nwpw/pspw/minimizer/cgsd_bybminimize0.dev

diff --git a/Nwpw/pspw/minimizer/cgsd_bybminimize0.dev b/Nwpw/pspw/minimizer/cgsd_bybminimize0.dev
new file mode 100644
index 00000000..25f379d5
--- /dev/null
+++ b/Nwpw/pspw/minimizer/cgsd_bybminimize0.dev
@@ -0,0 +1,129 @@
+
+#include <cmath>
+#include <cstdio>
+#include <cstdlib>
+#include <iostream>
+#include <string>
+
+#include "Control2.hpp"
+#include "Geodesic.hpp"
+#include "Ion.hpp"
+#include "Molecule.hpp"
+#include "Parallel.hpp"
+#include "Pneb.hpp"
+#include "pspw_lmbfgs.hpp"
+#include "util_date.hpp"
+#include "util_linesearch.hpp"
+
+namespace pwdft {
+
+/* create dummy function call to Geodesic class functions */
+static Geodesic *mygeodesic_ptr;
+static double dummy_energy(double t) { return mygeodesic_ptr->energy(t); }
+static double dummy_denergy(double t) { return mygeodesic_ptr->denergy(t); }
+
+/******************************************
+ *                                        *
+ *            cgsd_bybminimize0           *
+ *                                        *
+ ******************************************/
+double cgsd_bybminimize0(Molecule &mymolecule, Geodesic *mygeodesic,
+                         pspw_lmbfgs &psi_lmbfgs, double *E, double *deltae,
+                         int iterations, int it_out, int it_in) 
+{
+
+   //iterations = control_H1_it_in()
+   //it_out     = control_H1_it_out()
+   //it_ortho   = control_H1_it_ortho()
+
+   bool done = false;
+   double tmin = 0.0;
+   double deltat_min = 1.0e-2;
+   double deltat;
+   double sum0, sum1, scale, total_energy;
+   double dE, max_sigma, min_sigma;
+   double Eold, dEold, Enew;
+   double tmin0, deltae0;
+
+   Pneb *mygrid = mymolecule.mygrid;
+   mygeodesic_ptr = mygeodesic;
+
+   /* get the initial gradient and direction */
+   double *G0 = mygrid->g_allocate(1);
+   double *S0 = mygrid->g_allocate(1);
+
+  //|-\____|\/-----\/\/->    Start Parallel Section    <-\/\/-----\/|____/-|
+
+  total_energy = mymolecule.psi_1get_Tgradient(G0);
+  sum1 = mygrid->gg_traceall(G0, G0);
+  Enew = total_energy;
+
+  if (current_iteration == 0) {
+    psi_lmbfgs.start(G0);
+    mygrid->gg_copy(G0, S0);
+  } else {
+    psi_lmbfgs.fetch(tmin, G0, S0);
+
+    // reset to gradient if <S0|G0> <= 0.0
+    double kappa = mygrid->gg_traceall(G0, S0);
+    if (kappa <= 0.0)
+      mygrid->gg_copy(G0, S0);
+  }
+
+  /******************************************
+   ****                                  ****
+   ****   Start of BFGS iteration loop   ****
+   ****                                  ****
+   ******************************************/
+  int it = 0;
+  tmin = deltat_min;
+  while ((!done) && ((it++) < it_in)) {
+    /* initialize the geoedesic line data structure */
+    dEold = mygeodesic->start(S0, &max_sigma, &min_sigma);
+
+    /* line search */
+    if (tmin > deltat_min)
+      deltat = tmin;
+    else
+      deltat = deltat_min;
+
+    tmin0 = tmin;
+    deltae0 = *deltae;
+
+    Eold = Enew;
+    Enew = util_linesearch(0.0, Eold, dEold, deltat, &dummy_energy,
+                           &dummy_denergy, 0.50, &tmin0, &deltae0, 2);
+    tmin = tmin0;
+    *deltae = deltae0;
+    *deltac = mymolecule.rho_error();
+    mygeodesic->psi_final(tmin);
+
+    /* exit loop early */
+    done = ((it >= it_in) || ((std::fabs(*deltae) < tole) && (*deltac < tolc)));
+
+    /* make psi1 <--- psi2(tmin) */
+    mymolecule.swap_psi1_psi2();
+
+    if (!done) {
+      /* get the new gradient - also updates densities */
+      total_energy = mymolecule.psi_1get_Tgradient(G0);
+      psi_lmbfgs.fetch(tmin, G0, S0);
+
+      // reset to gradient if <S0|G0> <= 0.0
+      double kappa = mygrid->gg_traceall(G0, S0);
+      if (kappa <= 0.0)
+        mygrid->gg_copy(G0, S0);
+    }
+  }
+  // Making an extra call to electron.run and energy
+  total_energy = mymolecule.gen_all_energies();
+
+  //|-\____|\/-----\/\/->    End Parallel Section    <-\/\/-----\/|____/-|
+
+  mygrid->g_deallocate(S0);
+  mygrid->g_deallocate(G0);
+
+  return total_energy;
+}
+
+} // namespace pwdft