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Reliable radical stabilization energies from diffusion Monte Carlo calculations.
Manolo C Per1, Emily K Fletcher1, Ellen T Swann1
1CSIRO Data61, Docklands, Victoria, Australia.
Journal of Computational Chemistry
|August 12, 2020
Summary
Quantum Monte Carlo methods accurately calculate radical stabilization energies. Diffusion quantum Monte Carlo (DMC) is highly reliable, with all results within chemical accuracy, making it a potential benchmark for future studies.
Area of Science:
- Computational chemistry
- Quantum mechanics
- Chemical physics
Background:
- Radical stabilization energies are crucial for understanding chemical reactions.
- Accurate calculation of these energies is computationally challenging.
Purpose of the Study:
- To evaluate the performance of variational (VMC) and diffusion (DMC) quantum Monte Carlo methods.
- To assess their accuracy for calculating radical stabilization energies of carbon-centered radicals.
Main Methods:
- Utilized variational (VMC) and diffusion (DMC) quantum Monte Carlo.
- Employed simple single-determinant trial wavefunctions.
- Calculated radical stabilization energies for 43 carbon-centered radical species.
Main Results:
- Both VMC and DMC methods showed excellent performance.
- Mean absolute deviations were well below the 1 kcal/mol chemical accuracy standard.
- DMC demonstrated a highly concentrated error distribution, with all results within chemical accuracy at 95% confidence.
Conclusions:
- DMC is a highly reliable method for calculating radical stabilization energies.
- DMC can serve as a benchmark method for assessing larger, more complex systems in computational chemistry research.
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