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Insights to Orientation Dependence of Molecular Conduction Modeled by High-Level Quantum Embedding
Dávid P Jelenfi1,2, Abdalghani H S Daaoub3, Attila Tajti2
1György Hevesy Doctoral School, Institute of Chemistry, ELTE Eötvös Loránd University, Budapest, Hungary.
Journal of Computational Chemistry
|June 23, 2026
Summary
Conductance histograms reveal how molecular orientation and electrode interactions affect single-molecule junction conductance. Realistic structural sampling is crucial for accurately modeling these electronic transport properties.
Area of Science:
- Molecular electronics
- Quantum transport phenomena
- Computational condensed matter physics
Background:
- Single-molecule junctions are crucial for molecular electronics.
- Understanding conductance variations requires accurate theoretical models.
- Quantum embedding within the Non-Equilibrium Green's Function (NEGF) framework offers advanced simulation capabilities.
Purpose of the Study:
- To investigate the influence of molecular orientation and electrode-molecule interactions on conductance variations in single-molecule junctions.
- To evaluate the performance of various quantum embedding schemes and DFT methods in reproducing experimental conductance histograms.
- To assess the sensitivity of conductance histograms as a benchmark for theoretical transport methodologies.
Main Methods:
- Utilized quantum embedding within the NEGF framework.
- Generated conductance histograms from transmission functions for two experimentally studied systems.
- Assessed multiple embedding schemes and conventional DFT approaches against experimental data.
Main Results:
- The wavefunction-in-DFT, SOS-ADC(2)-in-PBE method offered the most balanced description of mean conductance and histogram width.
- No single method fully reproduced the behavior of the rigid dithienophosphole system, suggesting limitations in structural sampling.
- Conductance histograms proved to be sensitive benchmarks for theoretical methods.
Conclusions:
- Realistic configurational sampling is essential for accurate theoretical modeling of single-molecule junction conductance.
- Conductance histograms provide a valuable tool for evaluating and refining theoretical transport methodologies.
- Further development of computational methods is needed to fully capture complex molecular behaviors in junctions.
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