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Range-separated stochastic resolution of identity: Formulation and application to second-order Green's function
Wenjie Dou1, Ming Chen1, Tyler Y Takeshita2
1Department of Chemistry, University of California Berkeley, Berkeley, California 94720, USA.
The Journal of Chemical Physics
|August 24, 2020
Summary
A new range-separated stochastic resolution of identity (RS-SRI) method accelerates calculations for electron repulsion integrals. This approach significantly reduces errors and speeds up computations for molecular energies.
Area of Science:
- Computational chemistry
- Quantum chemistry
- Theoretical physics
Background:
- Calculating electron repulsion integrals is computationally intensive.
- Stochastic methods offer a potential speedup but often suffer from statistical errors.
- Accurate energy calculations are crucial for understanding molecular properties.
Purpose of the Study:
- To develop a more efficient and accurate method for calculating four-index electron repulsion integrals.
- To improve the computational scaling of quantum chemical calculations.
- To reduce the statistical error inherent in stochastic methods.
Main Methods:
- Developed a range-separated stochastic resolution of identity (RS-SRI) approach.
- Larger integral terms treated deterministically, smaller terms stochastically.
- Implemented within a second-order Green's function formalism with O(N^3) scaling.
Main Results:
- The RS-SRI approach significantly reduces statistical error compared to full stochastic methods.
- Achieved computational speedups of nearly two orders of magnitude for ground and excited state energies.
- Demonstrated efficiency on hydrogen dimer chains and water clusters.
Conclusions:
- The RS-SRI method offers a substantial improvement in computational efficiency and accuracy.
- This approach provides a viable path for accelerating quantum chemical calculations.
- The method is effective for studying molecular systems of varying sizes.
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