MC-PDFT-OPESf: Reaction Kinetics with Multireference Electronic Structure

MC-PDFT-OPESf couples multi-configuration pair-density functional theory (MC-PDFT) with on-the-fly enhanced sampling-flooding (OPESf) enhanced sampling via ASE, enabling efficient rate calculations for strongly correlated reactive systems.

📚 Requirements

To use MC-PDFT-OPESf, you'll need the following Python packages:

pip install pyscf ase

PLUMED (with Python interface)

Build PLUMED with the Python interface and set the kernel path:

export PLUMED_KERNEL=/path/to/libplumedKernel.so

Examples in the Paper

Diels-Alder Reaction of Butadiene and Ethylene (MC-PDFT + OPESf)

Inputs: da_opesf_plumed.dat, frame_da.xyz
MC-PDFT Settings: active space = (6e, 6o), on-top = tPBE

python src/PDFT_OPESf.py --method mc-pdft --xyz data/diels_alder/frame_da.xyz --plumed data/diels_alder/da_opesf_plumed.dat --basis 'ccpvdz' --ontop 'tPBE' --n_act 6 --n_elec 6 --charge 0 --spin 0 --dt 0.0005 --T 900 --n_step 1000000

SN2 Reaction of Methylchloride with Fluoride ion (KS-DFT + OPESf)

Inputs: sn2_opesf_plumed.dat, frame_sn2.xyz
KS-PDFT Settings: xc = b3lyp, basis = 6-31G*

python src/PDFT_OPESf.py --method ks-dft --xyz data/sn2/frame_sn2.xyz --plumed data/sn2/sn2_opesf_plumed.dat --basis '6-31G*' --xc 'b3lyp' --charge -1 --spin 0 --dt 0.0005 -T 1200 --n_step 1000000

📜 Citation

If you use MC-PDFT-OPESf in your research or publications, please cite the following:

@article{seal2025computing,
  title={Computing Reaction Kinetics with MC-PDFT--OPESf: Combining Multireference Electronic Structure Theory and Enhanced Sampling},
  author={Seal, Aniruddha and Gagliardi, Laura and Ferguson, Andrew L},
  journal={The Journal of Physical Chemistry Letters},
  volume={16},
  pages={11458--11463},
  year={2025},
  publisher={ACS Publications}
}