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: mxl_driver --model qutip --port <port> --param "preset=tls, omega=0.242, mu12=187, orientation=2, pe_initial=1e-4"
  • Embedded: Molecule(driver="qutip", driver_kwargs={"preset": "tls", "omega": 0.242, "mu12": 187, "orientation": 2, "pe_initial": 1e-4})

Use custom-module mode

• Provide a Python file that defines build_model(**kwargs) and returns H0, mu_ops, optional c_ops, and optional rho0.
  • Socket (module next to the job): mxl_driver --model qutip --port <port> --param "preset=custom, module=hcn_qutip.py"
  • Socket (absolute path): mxl_driver --model qutip --port <port> --param "preset=custom, module=/abs/path/spec.py"
  • Embedded: Molecule(driver="qutip", driver_kwargs={"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.