using LinearAlgebra

# Define the tight binding Hamiltonian
function tight_binding_hamiltonian(n_sites::Int64, t::Float64)
    H = zeros(n_sites, n_sites)
    for i in 1:(n_sites-1)
        H[i, i+1] = t
        H[i+1, i] = t
    end
    H
end

# Find the eigenenergies of the Hamiltonian
function eigenenergies(H::Array{Float64, 2})
    eigvals(H)
end

n_sites = 10 # number of sites in the chain
t = 1.0 # hopping parameter
H = tight_binding_hamiltonian(n_sites, t)
energies = eigenenergies(H)
println(energies)