This paper introduces a matrix-free tensor framework to address the computational challenges of many-body perturbation theory (MBPT) and coupled-cluster (CC) methods in quantum chemistry. The proposed approach combines tensor hypercontraction, interpolative separable density fitting, and iterative subspace methods to achieve reduced-scaling calculations, eliminating the need for explicit construction and storage of high-dimensional tensors.
Key findings
Unified theoretical framework for matrix-free MBPT calculations.
Algorithmic implementations for MP2, MP3, and CCSD with O(N3)–O(N4) complexity.
Comprehensive experimental design with benchmarks and error analysis.
Risk assessment with mitigation strategies for routine application to large systems.
Limitations & open questions
The proposed methods need extensive validation against existing quantum chemistry methods.
The scalability to very large systems with hundreds of atoms requires further testing.