QuTiP driver (model Hamiltonians)

Confirm prerequisites

• Ensure qutip is installed in the driver environment; import failures are expected otherwise.

Use preset TLS mode

• Prefer passing TLS parameters as top-level tokens to avoid comma-parsing confusion:

- Socket: mxldriver --model qutip --port <port> --param "preset=tls, omega=0.242, mu12=187, orientation=2, peinitial=1e-4" - Embedded: Molecule(driver="qutip", driverkwargs={"preset": "tls", "omega": 0.242, "mu12": 187, "orientation": 2, "peinitial": 1e-4})

Use custom-module mode

• Provide a Python file that defines buildmodel(**kwargs) and returns H0, muops, optional c_ops, and optional rho0.

- Socket (module next to the job): mxldriver --model qutip --port <port> --param "preset=custom, module=hcnqutip.py" - Socket (absolute path): mxldriver --model qutip --port <port> --param "preset=custom, module=/abs/path/spec.py" - Embedded: Molecule(driver="qutip", driverkwargs={"preset": "custom", "module": "hcn_qutip.py"}) - Ensure the driver process can import the module: - Launch the driver from the directory that contains the module, or - Add that directory to PYTHONPATH, or - Use an absolute module=... path on shared filesystem.

Notes

• Use fd_dmudt=true only when an analytical dipole-current expression is unavailable or unstable.
• For example setups, compare to tests/test_qutip/ and docs/source/drivers/qutip.rst.