Silicene Crystal Structure: Strain and Tight-Binding Model

[barana]

Crystal structure silicene is belows:

Na=2; % Number of atoms
Nbnd=8; % number of bands
q=0.03;
w=0.30;
aa=2.28;
a=3.86;
Csoc=0;
EL=0;
POSx(1)=4.45714;
POSy(1)=0;
POSz(1)=0;
POSx(2)=2.22857;
POSy(2)=0;
POSz(2)=0.46;
a1x=a*sqrt(3)/2;
a1y=-a/2;
a2x=a*sqrt(3)/2;
a2y=a/2;

sho=0;
for is=[0,-1,1]
  for js=[0,-1,1]
  for ks=1:Na
  sho=sho+1;
  X(sho)=POSx(ks)+(is*a1x+js*a2x);
  Y(sho)=POSy(ks)+(is*a1y+js*a2y);
  Z(sho)=POSz(ks);
  Ax(sho)=(is*a1x+js*a2x);  % Vector for uint cell
  Ay(sho)=(is*a1y+js*a2y);
  No(sho)=ks;
  L0=sqrt(((POSx(2)-POSx(1))^2+(POSy(2)-POSy(1))^2+(POSz(2)-POSz(1))^2));
  end
  end
end

I wants to insert strain in x-axis directions in tight binding model. How to changes top programs in the presence of strain? Is it only the lattice constant change (a=a0 (1+e))?

 

[BigJDubs]

Yes, it is only the lattice constant that needs to be changed in order to introduce strain in a tight binding model. In addition to changing the lattice constant, you may also need to adjust other parameters such as the hopping parameter (t), or the on-site energy (E0), depending on the type of strain you are introducing.