Commit ffa583a0 by Francois Gygi

Remove old kpgen.C, replaced by util/kpgen/kpgen.cpp

parent 2e5500e1
//
// kpgen.C: generate a kpoint list for an arbitrary cell
// use: kpgen nx ny nz sx sy sz a0x a0y a0z a1x a1y a1z a2x a2y a2z
//
// where a0x a0y a0z = first basis vector of the unit cell
// a1x a1y a1z = second basis vector of the unit cell
// a2x a2y a2z = third basis vector of the unit cell
//
// nx,ny,nz: number of kpoints in each direction
// sx,sy,sz: shift in each direction (floating point)
// shift: 0: symmetric set: boundary points not included
// even-numbered sets do not include the gamma point
// odd-numbered sets include the gamma point
//
#include<iostream>
#include<fstream>
#include<iomanip>
#include<vector>
#include<cassert>
#include<cstdlib>
#include<list>
#include "D3vector.h"
using namespace std;
// ib_BZ: test if the vector k is in the BZ defined by b0,b1,b2
bool in_BZ(D3vector k, D3vector b0, D3vector b1, D3vector b2)
{
const double epsilon = 1.e-8;
D3vector g;
// check projection of kpoint k along all 26 reciprocal lattice vectors
// that are nearest g=0
bool in_bz = true;
for ( int i0 = -1; i0 <= 1; i0++ )
for ( int i1 = -1; i1 <= 1; i1++ )
for ( int i2 = -1; i2 <= 1; i2++ )
if ( !(i0 == 0 && i1 == 0 && i2 == 0) )
{
D3vector g = i0 * b0 + i1 * b1 + i2 * b2;
if ( k*g > 0.5 * g*g + epsilon )
in_bz = false;
}
return in_bz;
}
int main(int argc, char** argv)
{
cout << "# kpgen-1.0" << endl;
if ( argc != 16 )
{
cerr << " use: " << argv[0] << " nx ny nz shiftx shifty shiftz {cell}"
<< endl;
cerr << " shift==0: symmetric set, zone boundary not included" << endl;
return 1;
}
int nx = atoi(argv[1]);
int ny = atoi(argv[2]);
int nz = atoi(argv[3]);
double sx = atof(argv[4]);
double sy = atof(argv[5]);
double sz = atof(argv[6]);
if ( nx <= 0 || ny <= 0 || nz <=0 )
{
cerr << " use: " << argv[0] << " nx ny nz shiftx shifty shiftz {cell}"
<< endl;
cerr << " nx, ny, nz must be positive" << endl;
return 1;
}
if ( sx < 0 || sx > 1 ||
sy < 0 || sy > 1 ||
sz < 0 || sz > 1 )
{
cerr << " use: " << argv[0] << " nx ny nz shiftx shifty shiftz {cell}"
<< endl;
cerr << " shifts must be in [0,1]" << endl;
return 1;
}
D3vector a0(atof(argv[7]),atof(argv[8]),atof(argv[9]));
D3vector a1(atof(argv[10]),atof(argv[11]),atof(argv[12]));
D3vector a2(atof(argv[13]),atof(argv[14]),atof(argv[15]));
const double volume = a0 * ( a1 ^ a2 );
if ( volume == 0.0 )
{
cout << " cell volume is zero" << endl;
return 1;
}
double fac = 2.0 * M_PI / volume;
D3vector b0 = fac * a1 ^ a2;
D3vector b1 = fac * a2 ^ a0;
D3vector b2 = fac * a0 ^ a1;
list<vector<int> > kplist;
vector<int> kpint(4);
// scan volume enclosing the BZ
for ( int ii = -2; ii <= 2; ii++ )
for ( int jj = -2; jj <= 2; jj++ )
for ( int kk = -1; kk <= 2; kk++ )
for ( int i = 0; i < nx; i++ )
{
for ( int j = 0; j < ny; j++ )
{
for ( int k = 0; k < nz; k++ )
{
kpint[0] = ii*2*nx + 2*i-nx+1;
kpint[1] = jj*2*ny + 2*j-ny+1;
kpint[2] = kk*2*nz + 2*k-nz+1;
kpint[3] = 1;
D3vector k = kpint[0]/(2.0*nx) * b0 +
kpint[1]/(2.0*ny) * b1 +
kpint[2]/(2.0*nz) * b2;
if ( in_BZ(k,b0,b1,b2) )
kplist.push_back(kpint);
}
}
}
int total_weight = kplist.size();
#if 1
// remove -k
for (list<vector<int> >::iterator i = kplist.begin(); i != kplist.end(); i++)
{
// test if -k is in the set (and is not 0 0 0)
kpint[0] = (*i)[0];
kpint[1] = (*i)[1];
kpint[2] = (*i)[2];
kpint[3] = (*i)[3];
if ( kpint[0]*kpint[0]+kpint[1]*kpint[1]+kpint[2]*kpint[2] != 0 )
{
// look for -k in the rest of the list
for ( list<vector<int> >::iterator j = i; j != kplist.end(); j++ )
{
if ( (*j)[0]==-kpint[0] && (*j)[1]==-kpint[1] && (*j)[2]==-kpint[2] )
{
// transfer weight to (*i)
(*i)[3] += (*j)[3];
(*j)[3] = 0;
//cout << " erasing " << "(" << kpint[0] << ","
// << kpint[1] << "," << kpint[2] << ") == -("
// << (*j)[0] << "," << (*j)[1] << "," << (*j)[2] << ")" << endl;
}
}
}
}
#endif
#if 1
// remove equivalent points
for (list<vector<int> >::iterator i = kplist.begin(); i != kplist.end(); i++)
{
D3vector ki = (*i)[0]/(2.0*nx) * b0 +
(*i)[1]/(2.0*ny) * b1 +
(*i)[2]/(2.0*nz) * b2;
// look for equivalent points in the rest of the list
for ( list<vector<int> >::iterator j = i; j != kplist.end(); j++ )
{
if ( j != i )
{
D3vector kj = (*j)[0]/(2.0*nx) * b0 +
(*j)[1]/(2.0*ny) * b1 +
(*j)[2]/(2.0*nz) * b2;
if ( length(ki-kj) < 1.e-5 )
{
// transfer the weight of kj to ki
(*i)[3] += (*j)[3];
(*j)[3] = 0;
//cout << " erasing equivalent point " << "(" << (*j)[0] << ","
// << (*j)[1] << "," << (*j)[2] << ") == ("
// << (*i)[0] << "," << (*i)[1] << "," << (*i)[2] << ")" << endl;
}
}
}
}
#endif
// remove elements with zero weight
for (list<vector<int> >::iterator i = kplist.begin();
i != kplist.end(); /* nothing */ )
{
if ( (*i)[3] == 0 )
{
kplist.erase(i++);
}
else
{
i++;
}
}
#if 1
// make first index positive
for (list<vector<int> >::iterator i = kplist.begin(); i != kplist.end(); i++)
{
D3vector ki = (*i)[0]/(2.0*nx) * b0 +
(*i)[1]/(2.0*ny) * b1 +
(*i)[2]/(2.0*nz) * b2;
if ( ki.x < 0 )
{
(*i)[0] *= -1;
(*i)[1] *= -1;
(*i)[2] *= -1;
}
}
#endif
#if 1
// check that the sum of weights is one
int sum = 0;
for (list<vector<int> >::iterator i = kplist.begin(); i != kplist.end(); i++)
{
sum += (*i)[3];
}
assert(sum==total_weight);
#endif
#if 1
// output list
// traverse list backwards to have increasing indices
// kpoints are output in reciprocal lattice coordinates
cout.setf(ios::right,ios::adjustfield);
cout << "# nx,ny,nz: " << nx << " " << ny << " " << nz << endl;
cout << "# sx,sy,sz: " << sx << " " << sy << " " << sz << endl;
cout << "# a0: " << a0 << endl;
cout << "# a1: " << a1 << endl;
cout << "# a2: " << a2 << endl;
cout << "# b0/(2pi): " << b0/(2*M_PI) << endl;
cout << "# b1/(2pi): " << b1/(2*M_PI) << endl;
cout << "# b2/(2pi): " << b2/(2*M_PI) << endl;
cout << "# " << kplist.size() << " k-points" << endl;
cout << " kpoint delete 0 0 0" << endl;
for (list<vector<int> >::reverse_iterator i = kplist.rbegin();
i != kplist.rend(); i++)
{
cout.setf(ios::fixed,ios::floatfield);
cout << " kpoint add "
<< setprecision(10)
<< setw(13) << ((*i)[0]+sx)/(2.0*nx) << " "
<< setw(13) << ((*i)[1]+sy)/(2.0*ny) << " "
<< setw(13) << ((*i)[2]+sz)/(2.0*nz) << " ";
cout.setf(ios::scientific,ios::floatfield);
cout << setprecision(14)
<< setw(16) << (*i)[3]/((double) total_weight)
<< endl;
}
// output list in absolute coordinates for plot
ofstream plotfile("kpoint.plt");
for (list<vector<int> >::reverse_iterator i = kplist.rbegin();
i != kplist.rend(); i++)
{
D3vector k = (((*i)[0]+sx)/(2.0*nx)) * b0 / (2*M_PI) +
(((*i)[1]+sy)/(2.0*ny)) * b1 / (2*M_PI) +
(((*i)[2]+sz)/(2.0*nz)) * b2 / (2*M_PI);
plotfile.setf(ios::fixed,ios::floatfield);
plotfile << setprecision(8)
<< setw(13) << k.x << " "
<< setw(13) << k.y << " "
<< setw(13) << k.z << endl;
}
#endif
}
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