Andy Jiang

Refactor Incremental Fock Builds in Chain-of-Spheres Exchange

25

## Description Through tests of the `COSX` code, we have discovered numerical instabilities in larger systems, leading to slow convergence for later iterations. We discovered that the version of incremental...

CFMM Part 1/3: Add Libfmm and Multipole Translation and Rotation Functions

19

## Description This is the First PR in a series of three that will eventually get White and Head-Gordon's CFMM method into Psi4. CFMM is a method that builds J-like...

[Draft] DLPNO-CCSD PR

2

## Description HERE IT IS!!! This is a draft of the DLPNO-CCSD PR that will be coming in the next few months. The purpose of this is for the developers...

Least Squares Tensor Hypercontraction (LS-THC) for ERIs (Part 1)

2

## Description In this PR, we implement a pilot version of least squares tensor hypercontraction (LS-THC)... factoring 4-index ERIs (O(N^4)) into two-index quantities (i.e. $(mn|rs) = x_{m}^{P}x_{n}^{P}Z^{PQ}x_{r}^{Q}x_{s}^{Q}$). In the LS-THC...

Least Squares Tensor Hypercontraction (LS-THC) for ERIs (Part 2): Grid Pruning

1

## Description This PR implements the grid pruning scheme of Matthews (https://pubs.acs.org/doi/10.1021/acs.jctc.9b01205), applying a pivoted Cholesky decomposition to the S matrix to remove linear dependencies and drastically reduce the number...

DLPNO-CCSD(T)

2

## Description The official PR to make DLPNO-CCSD(T) officially part of Psi4, as described in the following paper: https://pubs.aip.org/aip/jcp/article/161/8/082502/3309340/Accurate-and-efficient-open-source-implementation **Code still subject to cleanup, but it is fully functional!** ##...

[DRAFT] DLPNO-CCSDT(Q)!!!

1

## Description This is a draft of the DLPNO-CCSDT(Q) method that will eventually be available in Psi4, described in these two works: [DLPNO-CCSDT](https://doi.org/10.1021/acs.jctc.4c01716) [DLPNO-CCSDT(Q)](https://doi.org/10.1063/5.0257672) This is currently research-quality software for...