name: mxl-driver-psi4-rtehrenfest
description: This skill should be used when users want to run the Psi4 RT-Ehrenfest driver (rtehrenfest) with MaxwellLink and need parameters, charge conventions, and socket/embedded invocation patterns.

Psi4 RT-Ehrenfest driver (rtehrenfest)

Confirm prerequisites

• Ensure psi4 is installed and importable in the driver environment.
• Provide an XYZ geometry file whose second line specifies charge and multiplicity (e.g., 0 1).

Configure socket mode

• Run:
• mxl_driver --model rtehrenfest --address <host> --port <port> --param "molecule_xyz=../HCN_benchmark/hcn.xyz, functional=b3lyp, basis=cc-pvdz, dt_rttddft_au=0.04788, dft_grid_name=SG1, memory=2GB, num_threads=1, force_type=ehrenfest, n_fock_per_nuc=6, n_elec_per_fock=6"

Configure embedded mode

• Instantiate:
• Molecule(driver="rtehrenfest", driver_kwargs={...})

Notes

• Use force_type=bo when nuclear gradients from Born–Oppenheimer surfaces are required; use force_type=ehrenfest for mean-field forces.
• When passing partial_charges on the command line, use a space-separated list in brackets (no commas), e.g. partial_charges=[1.0 -1.0 0.0].
• On HPC, match num_threads to --cpus-per-task (single driver) or set num_threads=1 when launching many drivers in the same SLURM job.
• Read full parameter docs in docs/source/drivers/rtehrenfest.rst.