Related Experiment Video
Updated: Dec 5, 2025
Multiscale Sampling of a Heterogeneous Water/Metal Catalyst Interface using Density Functional Theory and Force-Field Molecular Dynamics
Published on: April 12, 2019
Benchmarking an Embedded Adaptive Sampling Configuration Interaction Method for Surface Reactions: H2 Desorption from
Qing Zhao1, Xing Zhang1, John Mark P Martirez1
1Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544-5263, United States.
Embedded correlated wavefunction theory accurately models catalytic reactions. While adaptive sampling configuration interaction (ASCI) allows larger active spaces, it underperforms compared to embedded multireference second-order perturbation theory (emb-MRPT2) for surface reactions, necessitating further correlation treatment.
Area of Science:
- Computational Chemistry
- Surface Science
- Heterogeneous Catalysis
Background:
- Embedded correlated wavefunction (CW) theory is crucial for understanding catalytic reaction mechanisms.
- Embedded multireference second-order perturbation theory (emb-MRPT2) using embedded complete active space self-consistent field (emb-CASSCF) is the current state-of-the-art.
- The factorial scaling of CASSCF limits system size and active space complexity.
Purpose of the Study:
- To assess the efficacy of adaptive sampling configuration interaction (ASCI) coupled with density functional embedding theory (DFET) for surface reactions.
- To benchmark ASCI-DFET against emb-MRPT2 for H2 desorption and CH4 dissociation on Cu(111).
Main Methods:
- Coupling adaptive sampling configuration interaction (ASCI) with density functional embedding theory (DFET).
- Benchmarking against embedded complete active space second-order perturbation theory (emb-CASPT2) and embedded Møller-Plesset second-order perturbation theory (emb-MP2).
- Investigating H2 desorption and CH4 dissociation reactions on the Cu(111) surface.
Main Results:
- Embedded ASCI (eASCI) failed to accurately reproduce the H2 desorption barrier, unlike emb-CASPT2.
- Adding dynamic correlation via embedded Møller-Plesset second-order perturbation theory (emb-MP2) improved eASCI predictions for H2 desorption and CH4 dissociation barriers.
- The composite eASCI + emb-MP2 approach suffered from double counting of correlation.
Conclusions:
- State-of-the-art emb-MRPT2 based on emb-CASSCF remains the preferred method for surface reaction studies.
- eASCI is valuable for complex surface reactions with significant static correlation but weak dynamic correlation, where large active spaces are essential.
- Further development is needed to address the limitations of eASCI in capturing dynamic correlation accurately.
