Bootstrap Embedding For Large Molecular Systems

Abstract

Recent developments in quantum embedding theories have provided attractive approaches to correlated calculations for large systems. In this work, we extend our previous work [J. Chem. Theory Comput. 2019, 15, 4497–4506; J. Phys. Chem. Lett. 2019, 10, 6368–6374] on bootstrap embedding (BE) to enable correlated ab initio calculations at the coupled cluster with singles and doubles (CCSD) level for large molecules. We introduce several new algorithmic developments that significantly reduce the computational cost of BE, while maintaining its accuracy. The resulting implementation scales as O(N 3) for the integral transform and O(N) for the CCSD calculation. Numerical results on a series of conjugated molecules suggest that BE with reasonably sized fragments can recover more than 99.5% of the total correlation energy of a full CCSD calculation, while the required computational resources (time and storage) compare favorably to one popular local correlation scheme: domain localized pair natural orbital (DLPNO). The largest BE calculation in this work involves ∼2900 basis functions and can be performed on a single node with 16 CPU cores and 64 GB of memory in a few days. We anticipate that these developments represent an important step toward the application of BE to solve practical problems.

Correlation-consistent Gaussian basis sets for solids made simple

“…Although our basis sets were tested using MP2, they will be valuable in work using more accurate ab initio correlated methods, such as coupled-cluster theory, [7][8][9]11,12,29 auxiliary field quantum Monte Carlo, 28,[88][89][90][91] or quantum embedding approaches. [92][93][94][95][96][97][98][99][100] In particular, our basis sets remain to be tested on three-dimensional metals, where MP2 is inapplicable. 101 Reliable and standardized Gaussian basis sets for periodic systems also call for the development of optimized auxiliary basis sets for density fitting.…”

Molecule‐Specific Uncertainty Quantification in Quantum Chemical Studies

“…[140][141][142][143] To obtain accurate electronic structures and energies for molecules of increasing size, one may resort to embedding approaches (see Refs. [144][145][146] and references therein) so that the quantum region which must be accurately described remains to be of constant size.…”

Quantum embedding electronic structure methods

“…Similar embedding methods requiring the definition of a supersystem Hilbert space are those that reproduce KS‐DFT while aiming to reduce the cost, for example, bootstrap embedding [ 34,35 ] and the projection‐based embedding methods developed initially by the Piela group [ 36 ] and more recently revived by the Chalasinski group [ 37 ] in the context of symmetry adapted perturbation theory (SAPT) and by the groups of Hoffman, [ 38 ] Miller, [ 39–41 ] Carter, [ 42–44 ] and Neugebauer [ 45 ] in the context of DFT‐in‐DFT and wavefunction‐in‐DFT embedding. These hinge upon partitioning the orbital space into orthogonal subspaces, while embedded mean field methods employ multiple representations of the DM [ 46–48 ] to use smaller basis sets associated with cheaper local functionals for selected atoms.…”

“…This very idea applies well to bulk crystals containing transition metal elements [32] of, even more extremely, lanthanides and actinides. [33] Similar embedding methods requiring the definition of a supersystem Hilbert space are those that reproduce KS-DFT while aiming to reduce the cost, for example, bootstrap embedding [34,35] and the projection-based embedding methods developed initially by the Piela group [36] and F I G U R E 1 Interactions during the Spring 2019 National ACS meeting in Orlando, Fl. A, Crowds in search of a lunch spot.…”