Tight binding s-orbital for 2D binary compound

[Braggplane]

Hi guys! I'm new to the forum, i hope you can help me with this trouble! it really is important =D

i have a 2D binary compound AB (made of one of the 100 family of planes of a rocksalt structure) and i am asked to "consider a single s-orbital on each atom (atomic energies Ea,Eb) and nearest neighbor hopping integrals between pairs of each of the atomic types (AA,BB,AB), neglecting overlap. Write the system of equations that one should solve in the tight binding approssimation, in terms of the hopping integrals (AA,BB,AB) and a (lattice constant)."

i have to discss that problem with my professor for the exam so please help me :S

 

[DrDu]

Do you have any concrete question? Can you specify a primitive cell for the rocksalt structure?

 

[Braggplane]

Do you have any concrete question? Can you specify a primitive cell for the rocksalt structure?

You can specify a triangular lattice with a one atom basis or a square lattice with a basis it makes no difference but i don't know how to to write the system of equations, because i know how to apply tight binding on elemental solids, it's a trouble with a binary compound

 

[DrDu]

Your primitive cell will contain 1 atom of A and one of B. You can express your atomic orbitals in terms of Bloch functions. If you do this, you should get a 2x2 matrix eigenvalue equation for each wavevector k.

 

[Braggplane]

Your primitive cell will contain 1 atom of A and one of B. You can express your atomic orbitals in terms of Bloch functions. If you do this, you should get a 2x2 matrix eigenvalue equation for each wavevector k.

Thanks DrDu, i was now with a phisicist and we figured out indeed this way! (i am an engineer XD)