The 16 energy eigenvectors of the Hubbard Hamiltonian for charge states N − 4 to N and their designation, under the assumption of equal site energies. σ = (↑,↓), Φ_A = |↑↓,0〉, Φ_B = |0,↑↓〉, Φ_C = |↑,↓〉 and Φ_D = |↓,↑〉. The coefficients c₊ and c₋ depend on the values of t, U, and V, as described in the text.

Charge state	Eigenstates of HHB	State (degeneracy)
N − 4	|0,0〉	SN−4 (1)
N − 3		D+,σN−3 (2)
		D−,σN−3 (2)
N − 2	c−(ΦA + ΦB) − c+(ΦC − ΦD)	S−N−2, (1)
		T0N−2, T1N−2T−1N−2 (3)
		SCSN−2, (1)
	c+(ΦA + ΦB) + c−(ΦC + ΦD)	S+N−2, (1)
N − 1		D+,σN−1, (2)
		D−,σN−1, (2)
N	|↑↓,↑↓〉	SN, (1)