# unsymmetric observable estimation by Qiskit

Assume $$|i\rangle,i\in[1,m]$$ is a set of states, like the Fock states for Fermions. The question is how to compute the quantity,$$\langle i |H|j\rangle,i,j\in[1,m]$$, in qiskit. The $$H$$ here is the qubit form Hamiltonian of some molecule obtained by the Jordan-Wigner transformation.

• You're looking for the matrix elements of $H$ in the basis $|i⟩$. Depending on what $|i⟩$ is, you can probably do so without qiskit. (Indeed, getting the matrix elements of $H$ is a starting point for chemistry calculations with qiskit!) Oct 19 at 16:19