def METHOD_NAME(core, active, t_op_exp):
    r"""Test the correctness of the FermionOperator built by the `'one_particle'` function
    of the `obs` module"""
    import openfermion
    hf = openfermion.MolecularData(filename=os.path.join(ref_dir, "h2o_psi4"))
    t_op = qchem.one_particle(hf.one_body_integrals, core=core, active=active)
    assert t_op.terms == t_op_exp