/** applet No. 1162
 *
 * dimer - jellium core - all electron - real space DFT-LSD
 * LSD:  J. P. Perdew and A. Zunger; Phys. Rev., B23, 5048 (1981)
 * - multi thread  LSD :: display - asynchronous
 *
 * Created by Ikeuchi Mitsuru on April 22 2007.
 * Copyright (c) 2007 Ikeuchi Mitsuru. All rights reserved.
 *
 * ver 0.0.1   2007.04.22  created
 * ver 0.0.2   2007.06.23  improved code
 *
 */

import java.awt.*;
import java.awt.event.*;
import java.applet.*;

public class dimerMtLSD extends Applet
  implements MouseListener, MouseMotionListener,
    ItemListener, ActionListener, AdjustmentListener, Runnable {

  // ------------------------------------ preset field -----------

  Thread th = null; // for run()-paint() thread
  RSDFTLSD rs = null;
  DrawGraph3d dg3d = new DrawGraph3d();

  // for event
  Choice ch_atom0, ch_atom1, ch_noe, ch_orbit, ch_view;
  Button bt_reset, bt_startStop;
  Scrollbar sc_ppDistance, sc_mixing, sc_broadening;

  // for off-paint buffer
  Dimension dim;
  Image imgOff;
  Graphics gOff;

  int dgX, dgY, dgXb,dgYb; // mouse

  int sleepTime = 50;
  int dispMode = 10;
  int thCount = 0;


  // ------------------------------ applet main thread -----------

  public void init() {

    resize(630,460);
    setBackground(Color.white);

    dim = getSize();
    imgOff = createImage(dim.width,dim.height);
    gOff = imgOff.getGraphics();

    ch_atom0 = new Choice();
    ch_atom0.add("H");ch_atom0.add("He");
    ch_atom0.add("Li");ch_atom0.add("Be");
    ch_atom0.add("B");ch_atom0.add("C");
    ch_atom0.add("N");ch_atom0.add("O");
    ch_atom0.add("F");
    ch_atom0.addItemListener(this);
    ch_atom0.select("C");

    ch_atom1 = new Choice();
    ch_atom1.add("H");ch_atom1.add("He");
    ch_atom1.add("Li");ch_atom1.add("Be");
    ch_atom1.add("B");ch_atom1.add("C");
    ch_atom1.add("N");ch_atom1.add("O");
    ch_atom1.add("F");
    ch_atom1.addItemListener(this);
    ch_atom1.select("O");

    ch_noe = new Choice();
    ch_noe.add("ne=Z-1");ch_noe.add("ne=Z-0.5");
    ch_noe.add("ne=Z");ch_noe.add("ne=Z+0.5");
    ch_noe.add("ne=Z+1");
    ch_noe.addItemListener(this);
    ch_noe.select("ne=Z");

    ch_orbit = new Choice();
    ch_orbit.add("ph-0");ch_orbit.add("ph-1");
    ch_orbit.add("ph-2");ch_orbit.add("ph-3");
    ch_orbit.add("ph-4");ch_orbit.add("ph-5");
    ch_orbit.add("ph-6");ch_orbit.add("ph-7");
    ch_orbit.add("ph-8");ch_orbit.add("ph-9");
    ch_orbit.add("ph-10");ch_orbit.add("ph-11");
    ch_orbit.add("ph-12");ch_orbit.add("ph-13");
    ch_orbit.add("ph-14");ch_orbit.add("ph-15");
    ch_orbit.add("ph-16");ch_orbit.add("ph-17");
    ch_orbit.add("ph-18");ch_orbit.add("ph-19");
    ch_orbit.addItemListener(this);
    ch_orbit.select("ph-8");

    ch_view = new Choice();
    ch_view.add("orbit dens");ch_view.add("orbit phase");
    ch_view.add("ph-grid");
    ch_view.add("Vext"); ch_view.add("VH"); 
    ch_view.add("VxcUp"); ch_view.add("VxcDown");
    ch_view.add("VeffUp"); ch_view.add("VeffDown");
    ch_view.add("rho 3D"); ch_view.add("rho 3D /2");
    ch_view.addItemListener(this);
    ch_view.select("rho 3D /2");


    bt_reset = new Button("reset");
    bt_reset.addActionListener(this);

    bt_startStop = new Button("start/stop");
    bt_startStop.addActionListener(this);

    sc_ppDistance = new Scrollbar(Scrollbar.HORIZONTAL,12,10,0,30);
    sc_ppDistance.addAdjustmentListener(this);

    sc_mixing = new Scrollbar(Scrollbar.HORIZONTAL,20,10,1,100);
    sc_mixing.addAdjustmentListener(this);

    sc_broadening = new Scrollbar(Scrollbar.HORIZONTAL,1,10,1,110);
    sc_broadening.addAdjustmentListener(this);

    addMouseListener(this);  
    addMouseMotionListener(this);

    setLayout(new BorderLayout());
    Panel pnl = new Panel();
    pnl.setLayout(new GridLayout(1,6,5,0));
    pnl.add(ch_atom0);
    pnl.add(ch_atom1);
    pnl.add(sc_ppDistance);
    pnl.add(sc_broadening);
    pnl.add(ch_orbit);
    pnl.add(ch_view);
    add(pnl,"North");

  }

  public void start() {
    if (rs == null) {
      rs = new RSDFTLSD();
      rs.start();
    }
    if (th == null) {
      th = new Thread(this);
      th.start();
    }
  }

  public void stop() {
    if (th != null) th = null;
    if (rs != null) rs = null;
  }


  // ---------------------------------- event listener -----------

  public void itemStateChanged(ItemEvent ev) {
    double zz,NOE;

    if (ev.getSource() == ch_atom0){
      zz = 1.0 + ch_atom0.getSelectedIndex();
      rs.setAtom(0,zz);
    } else if (ev.getSource() == ch_atom1){
      zz = 1.0 + ch_atom1.getSelectedIndex();
      rs.setAtom(1,zz);
    } else if (ev.getSource() == ch_noe){
      NOE = rs.getNuclearCarge() - 1.0 + 0.5*ch_noe.getSelectedIndex();
      rs.setNumberOfElectron(NOE);
    } else if (ev.getSource() == ch_orbit){
      dg3d.setDispObj( ch_orbit.getSelectedIndex() );
    } else if (ev.getSource() == ch_view){
      dispMode = ch_view.getSelectedIndex();
    }
  }

  public void actionPerformed(ActionEvent ev){
    if(ev.getSource() == bt_reset){ 
      rs.reset();
    } else if (ev.getSource() == bt_startStop){
      if (rs.getStartSW()==0) {
        rs.setStartSW(1);
      } else {
        rs.setStartSW(0);
      }
    }
  }

  public void adjustmentValueChanged(AdjustmentEvent ev){
    if (ev.getSource() == sc_ppDistance) {
	  rs.setppDistance( 0.25*sc_ppDistance.getValue() );
    } else if (ev.getSource() == sc_broadening) {
	  rs.setBroadening( 0.001*sc_broadening.getValue() );
    } else if (ev.getSource() == sc_mixing) { 
      rs.setMixing( 0.01*(double)(sc_mixing.getValue()) );
    }
  }

  public void mousePressed(MouseEvent ev){ }
  public void mouseReleased(MouseEvent ev){
    dgXb = 0; dgYb = 0;
    dgX = 0; dgY = 0;
  }
  public void mouseClicked(MouseEvent ev){ }
  public void mouseEntered(MouseEvent ev){ } 
  public void mouseExited (MouseEvent ev){ }

  public void mouseMoved  (MouseEvent ev){ }

  public void mouseDragged(MouseEvent ev){
    dgXb = dgX; dgYb = dgY;
    dgX=ev.getX();
    dgY=ev.getY();
    if (dgXb==0 && dgYb==0) {
      dgXb = dgX; dgYb = dgY;
    }
    dg3d.setViewDelta( (dgX-dgXb), (dgY-dgYb) );
  }



  // ========================= run() - paint() loop ==============

  public void run() {
    while (th != null) {
      thCount += 1;
      offPaint();
      repaint();
      try {
        Thread.sleep(sleepTime);
      } catch (InterruptedException e) { }
    }
  }

  public void update(Graphics g) {
    paint(g);
  }

  public void paint(Graphics g) {
    g.drawImage(imgOff,0,0,this);
  }

  public void offPaint() {
    if (rs != null) {
      dg3d.plotGraph(gOff, rs, dispMode, thCount);
    }
  }

}



// =============================== draw graph 3d class ===========

class DrawGraph3d {

  private Graphics gOff;
  private RSDFTLSD rs;

  private int NNx = rs.NNx;
  private int NNy = rs.NNy;
  private int NNz = rs.NNz;
  private double dx = rs.dx;
  private double dy = rs.dy;
  private double dz = rs.dz;
  private double xMax = NNx*dx;
  private double yMax = NNy*dy;
  private double zMax = NNz*dz;
  private double cxx = xMax/2.0;
  private double cyy = yMax/2.0;
  private double czz = zMax/2.0;

  private double dispScale = 240.0/xMax;
  private double viewScale = 1.0;
  private double scale = dispScale*viewScale;

  private int xImageLoc = 60;
  private int yImageLoc = 100;
  
  private int dispObj = 8;

  private double viewTheta = -15.0*3.14/180.0;
  private double viewFai = -72.0*3.14/180.0;
  private double cosTh = Math.cos(viewTheta); 
  private double sinTh = Math.sin(viewTheta);
  private double cosFi = Math.cos(viewFai);
  private double sinFi = Math.sin(viewFai);

  private double wkx[] = new double[8]; 
  private double wky[] = new double[8]; 
  private double wkz[] = new double[8]; 

  private double pwkx[] = new double[8]; 
  private double pwky[] = new double[8]; 
  private double pwkz[] = new double[8]; 

  private int boxp[][] = {
    {0,1},{0,2},{0,4},{1,3},{1,5},{2,3},{2,6},{4,5},{4,6},{3,7},{5,7},{6,7}
  };

  private int xpts[] = new int[500];
  private int ypts[] = new int[500];

  private int drawnCount = 0;


  // ------------------------------- class constructor -----------

  DrawGraph3d() {
  }


  // ----------------------------------- class methods -----------

  public void plotGraph(Graphics gg, RSDFTLSD rsdft, int dispMode, int thCount) {
    int rsCount,gb,i;

    gOff = gg;
    rs = rsdft;
    if (rs==null) return;
    rsCount = rs.getCount();
    //if (rsCount==drawnCount) return;
    //drawnCount = rsCount;

    gOff.setColor(Color.white);
    gOff.fillRect(0,0,630,460);

    if (dispMode==0) {
      densityPlot( 2, dispObj);

    } else if (dispMode==1) {
      densityPlot( 3, dispObj);

    } else if (dispMode==2) {
      gridFnPlot(rs.getOrbit(dispObj), 20.0);

    } else if (dispMode==3) {
      gridFnPlot(rs.getVext(), 1.0);

    } else if (dispMode==4) {
      gridFnPlot(rs.getVh(), 1.0);

    } else if (dispMode==5) {
      gridFnPlot(rs.getVxcUp(), 1.0);

    } else if (dispMode==6) {
      gridFnPlot(rs.getVxcDown(), 1.0);

    } else if (dispMode==7) {
      gridFnPlot(rs.getvvUp(), 1.0);

    } else if (dispMode==8) {
      gridFnPlot(rs.getvvDown(), 1.0);

    } else if (dispMode==9) {
      densityPlot(0, dispObj);

    } else if (dispMode==10) {
      densityPlot(1, dispObj);

    }

    gOff.setColor(Color.black);
    gOff.drawString("atom 0",630/6*0+10,40);
    gOff.drawString("atom 1",630/6*1+10,40);
    gOff.drawString("pp="+(int)(rs.getppDistance()*100+0.5)/100.0+"au",630/6*2+10,40);
    gOff.drawString("kT0="+(int)(rs.getBroadening()*1000+0.5)/1000.0+" ",630/6*3+10,40);
    gOff.drawString("orbit,spin"+rs.getSpin(dispObj)+"/2",630/6*4+10,40);
    gOff.drawString("view",630/6*5+20,40);

    gb = 360;
    gOff.setColor(Color.black);
    gOff.drawString("kT="+(float)(rs.getLevelWidth())+" au",gb,60);
    gOff.drawString("iteration="+rs.getCount()+" ",gb+150,60);
    gOff.drawString("box="+(int)(NNx*dx)+"x"+ +(int)(NNy*dy)+"x"+(int)(NNz*dz)+" au",gb,80);
    gOff.drawString("dx="+(int)(dx*100.0)/100.0+" au",gb+150,80);
    //gOff.drawString("V(r) = -Z/r (r>=Rc, Rc=0.2au)",gb,100);
    //gOff.drawString("		= -(Z/Rc)*(1.5-0.5*(r/Rc)^2) (r<Rc)",gb,115);
    gOff.drawString("V(r) = Vjc(|R0-r|) + Vjc(|R1-r|),",gb,100);
    gOff.drawString("  Vjc(ra) =-Z/ra (ra>=Rc, Rc=0.2au)",gb,115);
    gOff.drawString("			= -(Z/Rc)*(1.5-0.5*(ra/Rc)^2) (ra<Rc)",gb,130);

    gOff.drawString("total energy="+(float)rs.getTotalEnergy()+" au",gb,160);

    gOff.setColor(Color.black);
    gOff.drawString("No. spin  occupation",gb,180);
    gOff.drawString("energy",gb+180,180);
    for (i=0; i<rs.getNumberOfOrbit(); i++) {
      gOff.setColor(Color.getHSBColor((float)(0.66-0.65*rs.getOccupation(i)), 0.9f,0.8f));
      gOff.drawString(""+i+"",gb,200+12*i);
      if (rs.getSpin(i)==1) {
        gOff.drawString("up",gb+20,200+12*i);
      } else {
        gOff.drawString("down",gb+20,200+12*i);
      }

      gOff.drawString(" "+(float)(rs.getOccupation(i))+"",gb+70,200+12*i);
      gOff.drawString(" "+(float)(rs.getLevel(i))+"",gb+180,200+12*i);
    }

  }


  // ------------------------------------ plot methods -----------

  //
  // densityPlot(int mode, int orbit)
  //
  // mode: 0-density 1-half  2-orbit density 3-orbit phase
  //

  private void densityPlot(int mode, int orbit) {
    int i,j,k,ix,iy,ir,fp;
    int iBegin, iEnd, iInc, jBegin, jEnd, jInc, kBegin, kEnd, kInc;
    float orbden;
    double x,y,z,ppx,ppy,ppz,dens;
    double ptr[][][];

    ptr = rs.getOrbit(orbit);
    orbden = (float)(0.3+0.3*rs.getOccupation(orbit));

    fp = drawBox(0);
    iBegin = 0; iEnd = NNx; iInc = 1;
    if (wkx[fp]>10.0) {
      iBegin = NNx-1; iEnd = 0; iInc = -1;
    }
    jBegin = 0; jEnd = NNy; jInc = 1;
    if (wky[fp]>10.0) {
      jBegin = NNy-1; jEnd = 0; jInc = -1;
    }
    kBegin = 0; kEnd = NNz; kInc = 1;
    if (wkz[fp]>10.0) {
      kBegin = NNz-1; kEnd = 0; kInc = -1;
    }

    for (i=iBegin; ((i<iEnd && iInc>0) || (i>=iEnd && iInc<0)) ; i += iInc) {
      x = dx*i;
      for (j=jBegin; ((j<jEnd && jInc>0) || (j>=jEnd && jInc<0)) ; j += jInc) {
        y = dy*j;
        for (k=kBegin; ((k<kEnd && kInc>0) || (k>=kEnd && kInc<0)) ; k += kInc) {
          z = dz*k;

          dens = 0.0;
          if (mode<=1) {
            dens = 2.0*rs.getDensity(i,j,k); if (dens>0.999) dens = 0.999;
            gOff.setColor(Color.getHSBColor((float)(0.66-0.66*dens), 0.9f,0.9f));
            if (mode==1 && j>NNy/2) dens = 0.0;
          } else if (mode==2) {
            dens = 5.0*ptr[i][j][k]*ptr[i][j][k]; if (dens>0.999) dens = 0.999;
            gOff.setColor(Color.getHSBColor((float)(0.66-0.66*dens), orbden,0.9f));
          } else if (mode==3) {
            dens = 5.0*ptr[i][j][k]*ptr[i][j][k]; if (dens>0.999) dens = 0.999;
            if (ptr[i][j][k]>0.0) {
              gOff.setColor(Color.getHSBColor(0.33f, orbden,0.9f));
            } else {
              gOff.setColor(Color.getHSBColor(0.01f, orbden,0.9f));
            }
          }
          ir = (int)(10.0*dens+0.9);

          if (ir>0) {
            ppy = cosFi*(y-cyy)+sinFi*(z-czz) + cyy; 
            ppz = -sinFi*(y-cyy)+cosFi*(z-czz) + czz;
            ppx = cosTh*(x-cxx)+sinTh*(ppz-czz) + cxx; 
            ppz = -sinTh*(x-cxx)+cosTh*(ppz-czz) + czz;

            ix = (int)(scale*ppx)+xImageLoc;
            iy = (int)(scale*ppy)+yImageLoc;
			
            gOff.fillOval(ix-ir/2,iy-ir/2,ir,ir);
          }
        }
      }
    }

    drawBox(1);
  }

  // draw box

  private int drawBox(int imode) {
    int i,gx,gy,g2x,g2y,farPoint;
    double sc;

    if (imode==0) {
      setBox();
      rotateBox();
    }
    sc = dispScale*viewScale;
    farPoint = findFarPoint();

    for (i=0; i<12; i++) {
      gx = (int)(sc*pwkx[boxp[i][0]])+xImageLoc;
      gy = (int)(sc*pwky[boxp[i][0]])+yImageLoc;
      g2x = (int)(sc*pwkx[boxp[i][1]])+xImageLoc;
      g2y = (int)(sc*pwky[boxp[i][1]])+yImageLoc;
      if (imode==0) {
        if (boxp[i][0]==farPoint || boxp[i][1]==farPoint) { 
          gOff.setColor(Color.lightGray);
          gOff.drawLine(gx,gy, g2x, g2y);
        }
      } else if (imode==1) {
        if (boxp[i][0]!=farPoint && boxp[i][1]!=farPoint) { 
          gOff.setColor(Color.darkGray);
          gOff.drawLine(gx,gy, g2x, g2y);
        }
      }
    }
    return farPoint;
  }

  private int findFarPoint() {
    int i,im;
    double m;

    im = 0; m = pwkz[im];
    for (i=0; i<8; i++) {
      if (pwkz[i]<m) {
        m = pwkz[i];
        im = i;
      }
    }
    return(im);
  }

  private void setBox() {
    int i,ix,iy,iz;
    double ballSize;

    i=0;
    ballSize = 0.0*xMax;

    for (ix=0; ix<2; ix++) {
      for (iy=0; iy<2; iy++) {
        for (iz=0; iz<2; iz++) {
          wkx[i] = -0.5*ballSize+(xMax+ballSize)*(double)(ix);
          wky[i] = -0.5*ballSize+(yMax+ballSize)*(double)(iy);
          wkz[i] = -0.5*ballSize+(zMax+ballSize)*(double)(iz);
          i += 1;
        }
      }
    }
  }

  private void rotateBox() {
    int i;
 
    for (i=0; i<8; i++) {
      pwky[i] = cosFi*(wky[i]-cyy)+sinFi*(wkz[i]-czz) + cyy; 
      pwkz[i] = -sinFi*(wky[i]-cyy)+cosFi*(wkz[i]-czz) + czz;
      pwkx[i] = cosTh*(wkx[i]-cxx)+sinTh*(pwkz[i]-czz) + cxx; 
      pwkz[i] = -sinTh*(wkx[i]-cxx)+cosTh*(pwkz[i]-czz) + czz;
    }  
  }

  //

  void gridFnPlot(double fn[][][], double weight) {
    int nx,ny,nz, i,j,k, gbx,gby;
    int cx,cy,cz,zPos;
    double z,px,py,pz,sc;
    double ph2;

    nx = fn.length; ny = fn[0].length; nz = fn[0][0].length;
    zPos = nz/2;
    cx = nx/2;
    cy = ny/2;
    cz = 0;
    sc = 4.0;

    gbx = 30+(int)(cx/sc);
    gby = 20+(int)(cy/sc);
    k = zPos;

    for(j=0; j<ny; j += 2) {
      for (i=0; i<nx; i++) { 
        z = weight*fn[i][j][k] + cz;
        py = cosFi*(j-cy)+sinFi*(z-cz) + cy; 
        pz = -sinFi*(j-cy)+cosFi*(z-cz) + cz;
        px = cosTh*(i-cx)+sinTh*(pz-cz) + cx; 
        pz = -sinTh*(i-cx)+cosTh*(pz-cz) + cz;
        xpts[i] = (int)(sc*px)+gbx;
        ypts[i] = (int)(sc*py)+gby;
      }
      for (i=0; i<nx-1; i++) {
        gOff.setColor(Color.getHSBColor(0.66f,0.6f,0.9f));
        gOff.drawLine(xpts[i],ypts[i],xpts[i+1],ypts[i+1]);
      }
    }

    for(i=0; i<nx; i += 2) {
      for (j=0; j<ny; j++) {
        z = weight*fn[i][j][k] + cz;
        py = cosFi*(j-cy)+sinFi*(z-cz) + cy; 
        pz = -sinFi*(j-cy)+cosFi*(z-cz) + cz;
        px = cosTh*(i-cx)+sinTh*(pz-cz) + cx; 
        pz = -sinTh*(i-cx)+cosTh*(pz-cz) + cz;
        xpts[j] = (int)(sc*px)+gbx;
        ypts[j] = (int)(sc*py)+gby;
      }
      for (j=0; j<ny-1; j++) { 
        gOff.setColor(Color.getHSBColor(0.66f,0.6f,0.9f));
        gOff.drawLine(xpts[j],ypts[j],xpts[j+1],ypts[j+1]);
      }
    }
  }


  // ------------------------------------- I/O methods -----------

  public void setViewDelta(double xDisplacement, double yDisplacement) {
    viewTheta += 0.5*3.14159/180.0*xDisplacement;
    viewFai += 0.5*3.14159/180.0*yDisplacement;
    cosTh = Math.cos(viewTheta); 
    sinTh = Math.sin(viewTheta);
    cosFi = Math.cos(viewFai);
    sinFi = Math.sin(viewFai);
  }

  public void setDispObj(int obj) { dispObj = obj; }
  public int getDispObj() { return dispObj; }  

}



// =================================== RSDFT-LSD class ===========

class RSDFTLSD extends Thread {

  public static double dx = 1.0/4.0;
  public static double dy = 1.0/4.0;
  public static double dz = 1.0/4.0;

  public static int NNx = 64;
  public static int NNy = 64;
  public static int NNz = 64;

  private double ppDistance = 3.0;
  private double mixing = 0.2;
  private double broadening = 0.001;
  private double SDdump = 0.03;  
  private int setVhQ = 0;
  private double NOE = 14.0;
  private double Znuc = 14.0;
  private int Norbit = 20;
  private int NNs = 12;

  private double vvUp[][][] = new double[NNx][NNy][NNz];
  private double vvDown[][][] = new double[NNx][NNy][NNz];

  private double vvext[][][] = new double[NNx][NNy][NNz];
  private double vvh[][][] = new double[NNx][NNy][NNz];
  private double vvxcUp[][][] = new double[NNx][NNy][NNz];
  private double vvxcDown[][][] = new double[NNx][NNy][NNz];

  private double rhoUp[][][] = new double[NNx][NNy][NNz];
  private double rhoDown[][][] = new double[NNx][NNy][NNz];

  private int psis[][] = new int[Norbit][2];
  private double sdEnergy[] = new double[Norbit];
  private double sdState[][][][] = new double[NNs][NNx][NNy][NNz];
  private double occ[] = 
   { 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 
     1.0, 1.0, 1.0, 1.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0  };

  private double nuc[][] = {
    { 6.0, 8.0-2.0, 8.0, 8.0  },
    { 8.0, 8.0-2.0+ppDistance, 8.0, 8.0  },
    { 0.0, 0.0, 0.0, 0.0  }
  };

  private int resetSW = 0;
  private int startSW = 1;
  private int stepSW = 0;
  private int sleepTime = 0;
  private int stopSleepTime = 100;
  private int iterCount = 0;


  // ------------------------------- class constructor -----------

  RSDFTLSD() {
    setInitialCondition();
  }


  // -------------------------------------- thread run -----------

  public void run() {
    while (true) {
      iteration();
      if (sleepTime>0) {
        try {
          Thread.sleep(sleepTime);
        } catch (InterruptedException e) { }
      }
    }
  }


  // --------------------------- set initial condition -----------

  void setInitialCondition() {

    iterCount = 0;
	setVhQ = 0;
	clearRho();
    setPotential(Znuc);
    setState(Norbit);

  }

  private void setState(int npsi) {
    int i,j,k,ist,stateMax, ie;
    double pai = 3.14159265;

    stateMax = (npsi+1)/2;
    for (ist=0; ist<stateMax; ist++) {
      for (i=NNx/4; i<NNx*3/4; i++) {
        for (j=NNy/4; j<NNy*3/4; j++) {
          for (k=NNz/4; k<NNz*3/4; k++) {
            sdState[ist][i][j][k] = Math.random()-0.5;
          }
        }
      }
      normalize(sdState[ist]);
    }

    for (ie=0; ie<npsi; ie++) {
      psis[ie][0] = ie/2; // orbit
      psis[ie][1] = 1-2*(ie%2); // set spin
    }
  }

  void setPotential(double Znuc) {
    int i,j,k,inuc;
    double x0,y0,z0;
    double x,y,z,r,Rc,zn;

    Rc = 0.2;
    for (i=0;i<NNx;i++) {
      for (j=0;j<NNy;j++) {
        for (k=0;k<NNz;k++) {
          x = i*dx;
          y = j*dy;
          z = k*dz;
          vvext[i][j][k] = 0.0;
          for (inuc=0;inuc<100;inuc++) {
            if (nuc[inuc][0]<=0.0) break;
            zn = nuc[inuc][0];
            x0 = nuc[inuc][1]; y0 = nuc[inuc][2]; z0 = nuc[inuc][3];
            r = Math.sqrt((x-x0)*(x-x0)+(y-y0)*(y-y0)+(z-z0)*(z-z0));
            if (r<Rc) {
              vvext[i][j][k] += -zn/Rc*(1.5-0.5*r*r/(Rc*Rc));
            } else {
              vvext[i][j][k] += -zn/r;
            }
          }
          if (setVhQ==0) {
            vvh[i][j][k] = -(NOE/Znuc)*vvext[i][j][k];
          }
        }
      }
    }

    setVhQ = 1;
	
    for (i=0;i<NNx;i++) {
      for (j=0;j<NNy;j++) {
        k = 0;
        vvh[i][j][k] = -(NOE/Znuc)*vvext[i][j][k];
        k = NNz-1;
        vvh[i][j][k] = -(NOE/Znuc)*vvext[i][j][k];
      }
    }
    for (i=0;i<NNx;i++) {
      for (k=0;k<NNz;k++) {
        j = 0;
        vvh[i][j][k] = -(NOE/Znuc)*vvext[i][j][k];
        j = NNy-1;
        vvh[i][j][k] = -(NOE/Znuc)*vvext[i][j][k];
      }
    }
    for (j=0;j<NNy;j++) {
      for (k=0;k<NNz;k++) {
        i = 0;
        vvh[i][j][k] = -(NOE/Znuc)*vvext[i][j][k];
        i = NNx-1;
        vvh[i][j][k] = -(NOE/Znuc)*vvext[i][j][k];
      }
    }
  }

  private void clearRho() {
    int i,j,k;

    for (i=0; i<NNx; i++) {
      for (j=0; j<NNy; j++) {
        for (k=0; k<NNz; k++) {
          rhoUp[i][j][k] = 0.0;
          rhoDown[i][j][k] = 0.0;
        }
      }
	}
  }


  // --------------------------------------- iteration -----------

  private void iteration() {
    int i;

    if (resetSW==1) {
      setInitialCondition();
      resetSW = 0;
      startSW = 1;
    }

    if (startSW==1) {
      itherStep();
    } else {
      try {
        Thread.sleep(stopSleepTime);
      } catch (InterruptedException e) { }
    }
  }

  private void itherStep() {
    iterCount += 1;
    setVeff();
    SD(Norbit, 2, SDdump);
    sortState(Norbit);
    setOcc(Norbit,NOE);
  }

  // (1) ----- set Veff ( effective potential <-- electron density ) -----

  private void setVeff() {
    int i,j,k;

    setRho();
    poisson(2);
    setVxc();

    for (i=1;i<NNx-1;i++) {
      for (j=1;j<NNy-1;j++) {
        for (k=1;k<NNz-1;k++) {
          vvUp[i][j][k] = vvext[i][j][k]+vvh[i][j][k]+vvxcUp[i][j][k];
          vvDown[i][j][k] = vvext[i][j][k]+vvh[i][j][k]+vvxcDown[i][j][k];
        }
      }
    }
  }

  private void setRho() {
    int i,j,k,ie,ib;

    for (i=1; i<NNx-1; i++) {
      for (j=1; j<NNy-1; j++) {
        for (k=1; k<NNz-1; k++) {
          rhoUp[i][j][k] *= (1.0-mixing);
          rhoDown[i][j][k] *= (1.0-mixing);
          for (ie=0; ie<Norbit; ie++) {
            ib = psis[ie][0];
            if (occ[ie]<=0.0) break;
            if (psis[ie][1]==1) {
              rhoUp[i][j][k] += mixing*occ[ie]*(sdState[ib][i][j][k]*sdState[ib][i][j][k]);
            } else if (psis[ie][1]==-1) {
              rhoDown[i][j][k] += mixing*occ[ie]*(sdState[ib][i][j][k]*sdState[ib][i][j][k]);
            }
          }
        }
      }
    }
  }

  private void poisson(int iterMax) {
    int i,j,k,iter;
    double h2,w;

    h2 = 4.0*3.1416*dx*dx;
    w = 0.2;

    for (iter=1; iter<iterMax; iter++) {
      for (i=1; i<NNx-1; i++) {
        for (j=1; j<NNy-1; j++) {
          for (k=1; k<NNz-1; k++) {
            vvh[i][j][k] = vvh[i][j][k]+w*(vvh[i+1][j][k]+vvh[i-1][j][k]+vvh[i][j+1][k]+vvh[i][j-1][k]+vvh[i][j][k+1]+vvh[i][j][k-1]-6.0*vvh[i][j][k] +h2*(rhoUp[i][j][k]+rhoDown[i][j][k]));
          }
        }
      }
    }
  }

  // LSD Vxc: J.P. Perdew, A. Zunger; Phys. Rev. B 23 5048 (1981)

  private void setVxc() {
    int i,j,k;
    double rh, exc, drh, z, ddz, vxc, dedz;

    drh = 0.01; ddz=0.01;
    for (i=1; i<NNx-1; i++) {
      for (j=1; j<NNy-1; j++) {
        for (k=1; k<NNz-1; k++) {
          rh = rhoUp[i][j][k]+rhoDown[i][j][k]+1.0e-20;
          z = (rhoUp[i][j][k]-rhoDown[i][j][k])/rh;

          exc = epsxc(rh,z);
          vxc = exc + rh*(epsxc(rh+drh,z)-exc)/drh;
          dedz = 0.0;
          if (z+ddz<1.0) {
            dedz = (epsxc(rh,z+ddz)-exc)/ddz;
          } else {
            dedz = (exc-epsxc(rh,z-ddz))/ddz;
          }

          vvxcUp[i][j][k] = vxc+dedz*(1-z);
          vvxcDown[i][j][k] = vxc-dedz*(1+z);
        }
      }
    }
  }

  private double epsxc(double rho, double zz) {
    double rh3,rs,eexp,eexf,eecp,eecf,lnrs,excp,excf,sqrtrs,fz;

    rh3 = Math.pow(rho,0.33333333);
    rs = 0.6204/(rh3+1.0e-20);
    eexp = -0.738559*rh3;
    eexf = 1.25992*eexp;
    eecp=0.0;
    eecf=0.0;
    if (rs>=1.0) {
      sqrtrs = Math.sqrt(rs);
      eecp = -0.1423/(1.0+1.0529*sqrtrs+0.3334*rs);
      eecf = -0.0843/(1.0+1.3981*sqrtrs+0.2611*rs);
    } else {
      lnrs = Math.log(rs);
      eecp = 0.0311*lnrs-0.048+0.002*rs*lnrs-0.0116*rs;
      eecf = 0.01555*lnrs-0.0269+0.0007*rs*lnrs-0.0048*rs;
    }
    excp = eexp+eecp;
    excf = eexf+eecf;
    fz = (Math.pow(1+zz,1.33333333)+Math.pow(1-zz,1.33333333)-2.0)/0.519842;
    return ( excp+(excf-excp)*fz );
  }

  // (2) ----- steepest descent method -----

  private void SD(int stateMax, int iterMax, double dump) {
    int i,ist;

    for (i=0; i<iterMax; i++) {
      for (ist=0; ist<stateMax; ist++) {
        sdEnergy[ist] = steepestDescent(sdState[psis[ist][0]], psis[ist][1], dump);
      }
      GramSchmidt(stateMax);
    }
  }

  private double steepestDescent(double psi[][][], int spn, double dump) {
    int i,j,k;
    double h2,ei,wk;

    ei = 0.0;
    h2 = 2.0*dx*dx;
    if (spn==1) {
      ei = energyOf(psi,vvUp);
      for (i=1; i<NNx-1; i++) {
        for (j=1; j<NNy-1; j++) {
          for (k=1; k<NNz-1; k++) {
            psi[i][j][k] -= dump*((6.0*psi[i][j][k]-psi[i+1][j][k]-psi[i-1][j][k]-psi[i][j+1][k]-psi[i][j-1][k]-psi[i][j][k+1]-psi[i][j][k-1])/h2 + (vvUp[i][j][k]-ei)*psi[i][j][k]);
          }
        }
      }
      normalize(psi);
    } else if (spn==-1) {
      ei = energyOf(psi,vvDown);
      for (i=1; i<NNx-1; i++) {
        for (j=1; j<NNy-1; j++) {
          for (k=1; k<NNz-1; k++) {
            psi[i][j][k] -= dump*((6.0*psi[i][j][k]-psi[i+1][j][k]-psi[i-1][j][k]-psi[i][j+1][k]-psi[i][j-1][k]-psi[i][j][k+1]-psi[i][j][k-1])/h2 + (vvDown[i][j][k]-ei)*psi[i][j][k]);
          }
        }
      }
      normalize(psi);
    }
    return (ei);
  }

  private double energyOf(double psi[][][], double v[][][]) {
    int i,j,k;
    double h2,dv,s,sn;

    h2 = 2.0*dx*dx;
    dv = dx*dy*dz;
    s = 0.0; sn=0.0;
    for (i=1; i<NNx-1; i++) {
      for (j=1; j<NNy-1; j++) {
        for (k=1; k<NNz-1; k++) {
          s += psi[i][j][k]*((6.0*psi[i][j][k]-psi[i+1][j][k]-psi[i-1][j][k]-psi[i][j+1][k]-psi[i][j-1][k]-psi[i][j][k+1]-psi[i][j][k-1])/h2 + v[i][j][k]*psi[i][j][k])*dv;
          sn += psi[i][j][k]*psi[i][j][k]*dv;
        }
      }
    }
    return ( s/sn );
  }

  // Gram-Schmidt

  private void GramSchmidt(int stateMax) {
    int i,j,k,ist,istate;
    double s;

    normalize(sdState[0]);

    for (istate=1; istate<stateMax; istate++) {
      for (ist=0; ist<istate; ist++) {
        if (psis[ist][1]==psis[istate][1]) {
          s = innerProduct(sdState[psis[ist][0]],sdState[psis[istate][0]]);
          for (i=1; i<NNx-1; i++) {
            for (j=1; j<NNy-1; j++) {
              for (k=1; k<NNz-1; k++) {
                sdState[psis[istate][0]][i][j][k] -= s*sdState[psis[ist][0]][i][j][k];
              }
            }
          }
        }
      }
      normalize(sdState[psis[istate][0]]);
    }
  }

  private double innerProduct(double f[][][],double g[][][]) {
    int i,j,k;
    double s,dv;

    dv = dx*dy*dz;
    s = 0.0;
    for (i=1; i<NNx-1; i++) {
      for (j=1; j<NNy-1; j++) {
        for (k=1; k<NNz-1; k++) {
          s += f[i][j][k]*g[i][j][k];
        }
      }
    }
    s *= dv;
    return ( s );
  }

  private void normalize(double ph[][][]) {
    int i,j,k;
    double s,a,dv;

    dv = dx*dy*dz;
    s = 0.0;
    for (i=1; i<NNx-1; i++) {
      for (j=1; j<NNy-1; j++) {
        for (k=1; k<NNz-1; k++) {
          s += ph[i][j][k]*ph[i][j][k];
        }
      }
    }
    s *= dv;
    a = Math.sqrt(1.0/s);
    for (i=1; i<NNx-1; i++) {
      for (j=1; j<NNy-1; j++) {
        for (k=1; k<NNz-1; k++) {
          ph[i][j][k] = a*ph[i][j][k];
        }
      }
    }
  }

  // (3) ----- sort state -----

  private void sortState(int maxState){
    int ist,iw;
	double w;

    for (ist=maxState-2; ist>=0; ist--) {
      if (sdEnergy[ist]>sdEnergy[ist+1]+0.0001) {
        iw = psis[ist][0]; psis[ist][0]=psis[ist+1][0]; psis[ist+1][0]=iw;
        iw = psis[ist][1]; psis[ist][1]=psis[ist+1][1]; psis[ist+1][1]=iw;
        w = sdEnergy[ist]; sdEnergy[ist]=sdEnergy[ist+1];sdEnergy[ist+1]=w;
      }
    }
  }

  // (4) ----- set occupation -----

  private void setOcc(int maxState, double nElectron) {
    int i;
    double eUpper,eLower,eFermi,ntrial;

    eUpper = sdEnergy[maxState-1]+1.0;
    eLower = sdEnergy[0]-1.0;
    for (i=0;i<maxState;i++) {
    if(sdEnergy[i]>eUpper) eUpper = sdEnergy[i];
    if(sdEnergy[i]<eLower) eLower = sdEnergy[i];
    }

    while (eUpper-eLower>1.0e-12) {
      eFermi = (eUpper+eLower)/2.0;
      ntrial = trialOcc(maxState, eFermi);
      if (ntrial<nElectron) {
        eLower = eFermi;
      } else {
        eUpper = eFermi;
      }
    }
    eFermi = (eUpper+eLower)/2.0;

    for (i=0;i<maxState;i++) {
      occ[i] = 1.0*FermiDirac(sdEnergy[i], eFermi);
      if (occ[i]<0.0001) occ[i] = 0.0;
      if (1.0-occ[i]<0.0001) occ[i] = 1.0;
    }
  }

  private double trialOcc(int maxState, double eFermi) {
    int i;
    double s;

    s = 0.0;
    for (i=0;i<maxState;i++) {
      s += 1.0*FermiDirac(sdEnergy[i], eFermi);
    }
    return ( s );
  }

  private double FermiDirac(double ee, double ef) {
    double et;
    et = levelWidth();
    return ( 1.0/(Math.exp((ee-ef)/et)+1.0) );
  }

  private double levelWidth() {
    double kT;

    kT = broadening;
    if (iterCount<30) {
      kT=0.1;
    } else {
      kT = 0.1-0.002*(iterCount-29);
      if (kT<broadening) kT = broadening;
    }
    return ( kT );
  }


  // ----------------------------------------- utility -----------

  private double totalEnergy() {
    int i,j,k;
    double x,y,z,s,sei,enn;

    sei = 0.0;
    for (i=0;i<Norbit;i++) {
      if (occ[i]<=0.0) break;
      sei += occ[i]*sdEnergy[i];
    }

    enn = 0.0;
    for (i=0;i<100;i++) {
      if (nuc[i][0]<=0.0) break;
      for (j=i+1;j<100;j++) {
        if (nuc[j][0]<=0.0) break;
        x = nuc[i][1]-nuc[j][1];
        y = nuc[i][2]-nuc[j][2];
        z = nuc[i][3]-nuc[j][3];
        sei += nuc[i][0]*nuc[j][0]/Math.sqrt(x*x+y*y+z*z);
      }
    }

    s = 0.0;
    for (i=1;i<NNx-1;i++) {
      for (j=1;j<NNy-1;j++) {
        for (k=1;k<NNz-1;k++) {
          s += (-0.5*vvh[i][j][k]-0.25*vvxcUp[i][j][k])*rhoUp[i][j][k];
          s += (-0.5*vvh[i][j][k]-0.25*vvxcDown[i][j][k])*rhoDown[i][j][k];
        }
      }
    }
    s = s*dx*dy*dz;
	
    return ( enn+sei+s );
  }


  // ------------------------------------- I/O methods -----------

  // control
  public void reset() { resetSW = 1; }
  public void setStartSW(int sw) { startSW = sw; }
  public int getStartSW() { return startSW; }

  public void setAtom(int inuc, double zz) {
    nuc[inuc][0] = zz;
	Znuc = nuc[0][0] + nuc[1][0];
	NOE = Znuc;
    resetSW = 1;
  }
  public double getNuclearCarge() { return nuc[0][0]; }
  public void setNumberOfElectron(double ne) {
    NOE = ne;
    iterCount = 0;
  }
  public double getNumberOfElectron() { return NOE; }
  public int getNumberOfOrbit() { return Norbit; }

  public void setppDistance(double ppd) {
    ppDistance = ppd;
    nuc[1][1] = 32.0*dx-2.0+ppDistance;
    setVhQ = 1; setPotential(Znuc);
  }
  public double getppDistance() { return ppDistance; }
  public void setBroadening(double br) { broadening = br; }
  public double getBroadening() { return broadening; }
  public double getLevelWidth() { return levelWidth(); }
  public void setMixing(double mx) { mixing = mx; }
  public double getMixing() { return mixing; }

  // get data
  public int getCount() { return iterCount; }
  public double getTotalEnergy() { return totalEnergy(); }
  public double getOccupation(int i) { return occ[i]; }
  public double getLevel(int i) { return sdEnergy[i]; }
  public int getSpin(int i) { return psis[i][1]; }
  public double[][][] getOrbit(int i) { return sdState[psis[i][0]]; }

  public double getDensity(int i, int j, int k) { return rhoUp[i][j][k]+rhoDown[i][j][k]; }
  //public double[][][] getDensity() { return rhoUp; }
  public double[][][] getvvUp() { return vvUp; }
  public double[][][] getvvDown() { return vvDown; }
  public double[][][] getVext() { return vvext; }
  public double[][][] getVh() { return vvh; }
  public double[][][] getVxcUp() { return vvxcUp; }
  public double[][][] getVxcDown() { return vvxcDown; }
}