function epmV()
% based on Dragica Vasileska Empirical Pseudopotential Method
clc;
clear;

global ao N_pw igx_vec igy_vec igz_vec dkx dky dkz t Vs3 Va3 Vs8 Va8
global Vs11 Va11 ik_curr ik ek

str_fac = load('str_fac.txt');
a0 = load('a0.txt');
scn0 = fileread('semiconductors.txt');
scnames = strsplit(scn0);

Ry2eV=13.6056981d0;
hb=1.054D-34;
h=6.625D-34;
q=1.602d-19;
mo=9.11D-31;
t=hb*hb/2.0d0/mo/q;

NN_neighbours=10;
N_pw = 137;
N_ek=40;
ig2_mag(1:NN_neighbours)=[0, 3, 4, 8, 11, 12, 16, 19, 20, 24];
%sprintf('%s','This program calculates the bandstructure of semiconductors based on the Empirical Pseudopotential Method (EPM)')
%sprintf('%s','The following semiconductors are included')
%sprintf('1 -> Si 2 -> Ge 3 -> Sn 4 -> GaP 5 -> GaAs 6 -> AlSb 7 -> InP')
%sprintf('8 -> GaSb 9 -> InAs 10 -> InSb 11 -> ZnS 12 -> ZnSe 13 -> ZnTe 14 -> CdTe')

ichoose = 12;
ao=a0(ichoose);
Vs3=str_fac(ichoose,1);
Vs8=str_fac(ichoose,2);
Vs11=str_fac(ichoose,3);
Va3=str_fac(ichoose,4);
Va8=str_fac(ichoose,5);
Va11=str_fac(ichoose,6);
ao=ao*1.0d-10;
Vs3=Vs3*Ry2eV;
Vs8=Vs8*Ry2eV;
Vs11=Vs11*Ry2eV;
Va3=Va3*Ry2eV;
Va8=Va8*Ry2eV;
Va11=Va11*Ry2eV;

icount=0;
for i=1:NN_neighbours
ig2=ig2_mag(i);
a=sqrt(double(ig2));
ia=floor(a);
ic=0;
for igx=-ia:ia
   igx2=igx*igx;
   for jgy=-ia:ia
         jgy2=jgy*jgy;
         igxy2=igx2+jgy2;
         for kgz=-ia:ia
            kgz2=kgz*kgz;
            igxyz2=igxy2+kgz2;
            if (igxyz2==ig2)
               ic=ic+1;
               igx_vec(ic+icount)=igx;
               igy_vec(ic+icount)=jgy;
               igz_vec(ic+icount)=kgz;
            end
         end
   end
end
icount=icount+ic;
sprintf('%d %d %d',ig2,ic,icount);
end

fprintf('H1\r\n');
ik_curr=0;
sumx=0.0d0;
X0=0.5d0;
Y0=0.5d0;
Z0=0.5d0;
k_vec = zeros(1,161);
for ik=1:N_ek+1
dkx=0.50d0*(1.0d0-double(ik-1)/double(N_ek));
dky=0.50d0*(1.0d0-double(ik-1)/double(N_ek));
dkz=0.50d0*(1.0d0-double(ik-1)/double(N_ek));
generate_Hamil();
sumx=sqrt((X0-dkx)*(X0-dkx)+(Y0-dky)*(Y0-dky)+(Z0-dkz)*(Z0-dkz));
k_vec(ik+ik_curr)=sumx;

In procedure 2, trial 1, suppose you measure the ring to have mass...