# Qiskit Encoding of a Hamiltonian

I am not sure if this is a trivial question and I am just stuck or this is worth posting. I have a Hamiltonian, which is written in terms of Pauli matrices, such as

H = 4.5$$I$$ - 16 $$X_1$$ - 16 $$X_2$$ - 3.5 $$Z_1Z_4$$ -3.5 $$Z_1Z_2Z_3$$

and I would like to write it as a CH gate in qiskit to find the energy of the ground state. The idea is to write the Hamiltonian into matrix form and write $$\matrix{\mathbb{1}\ 0\\ 0\ H}$$ as a matrix.

Then use the QuantumCircuit.unitary() command to encode it. My issue is that H is non-unitary, this can be seen by already my first term 4.5$$I$$, where $$I$$ is $$\mathbb{1}$$. Is there a simple trick of encoding my Hamiltonian in a quantum circuit on qiskit?