Stochastic resolution of identity to CC2 for large systems: ground-state properties

2022/10/24 by Chongxiao Zhao, Zhao, Chongxiao, Wenjie Dou +1
Materials Science · Physics and Astronomy · #Advanced Chemical Physics Studies #Chemical Physics (physics.chem-ph) #FOS: Physical sciences #Machine Learning in Materials Science #Quantum, superfluid, helium dynamics

paper · pdf · doi:10.48550/arxiv.2210.12897

openalex publication_date 2022/10/24 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

A stochastic resolution of identity approach (sRI) is applied to the second-order coupled cluster singles and doubles (CC2) model to calculate the ground-state energy. Utilizing a set of stochastic orbitals to optimize the expensive tensor contraction steps in CC2, we greatly reduce the overall computational cost. Compared with the RI-CC2 model, the sRI-CC2 achieves scaling reduction from O(N⁵) to O(N³), where N is a measure for the system size. When applying the sRI-CC2 to a series of hydrogen dimer chains, we demonstrate that the sRI-CC2 accurately reproduces RI-CC2 results for the correlation energies and exhibits a scaling of O(NH².71), with NH being the number of hydrogen atoms. Our calculations with different systems and basis sets show small changes in standard deviations, which indicates a broad applicability of our approach to various systems.

Related

• Stochastic resolution of identity to CC2 for large systems: excited state properties
• Stochastic resolution of identity to CC2 for large systems: Oscillator strength and ground state gradient calculations
• Stochastic resolution of identity to CC2 for large systems: Excited-state gradients and derivative couplings
• Noise-reduced stochastic resolution of identity to CC2 for large-scale calculations via tensor hypercontraction
• Convergence Analysis of the Stochastic Resolution of Identity: Comparing Hutchinson to Hutch++ for the Second-Order Green's Function