# An integral-factorized implementation of the driven similarity renormalization group second-order multireference perturbation theory.

@article{Hannon2016AnII, title={An integral-factorized implementation of the driven similarity renormalization group second-order multireference perturbation theory.}, author={Kevin P Hannon and Chenyang Li and Francesco A. Evangelista}, journal={The Journal of chemical physics}, year={2016}, volume={144 20}, pages={ 204111 } }

We report an efficient implementation of a second-order multireference perturbation theory based on the driven similarity renormalization group (DSRG-MRPT2) [C. Li and F. A. Evangelista, J. Chem. Theory Comput. 11, 2097 (2015)]. Our implementation employs factorized two-electron integrals to avoid storage of large four-index intermediates. It also exploits the block structure of the reference density matrices to reduce the computational cost to that of second-order Møller-Plesset perturbation…

## 30 Citations

### Driven similarity renormalization group: Third-order multireference perturbation theory.

- Chemistry, PhysicsThe Journal of chemical physics
- 2017

The efficient implementation of the DSRG-MRPT3 based on factorized electron repulsion integrals enables studies of medium-sized open-shell organic compounds and leads to a non-iterative algorithm with O(N6) scaling, which includes reference relaxation effects.

### Analytic Energy Gradients for the Driven Similarity Renormalization Group Multireference Second-Order Perturbation Theory.

- PhysicsJournal of chemical theory and computation
- 2021

We derive analytic energy gradients of the driven similarity renormalization group (DSRG) multireference second-order perturbation theory (MRPT2) using the method of Lagrange multipliers. In the…

### Spin-free formulation of the multireference driven similarity renormalization group: A benchmark study of first-row diatomic molecules and spin-crossover energetics.

- Chemistry, PhysicsThe Journal of chemical physics
- 2021

A focal point analysis (FPA) shows that third-order perturbative corrections are essential to achieve reasonably converged energetics.

### Improving the efficiency of the multireference driven similarity renormalization group via sequential transformation, density fitting, and the non-interacting virtual orbital approximation.

- ChemistryJournal of chemical theory and computation
- 2019

The DF-sq-MR-LDSRG(2)+NIVO scheme can be applied to chemical systems with more than 550 basis functions by computing the automerization energy of cyclobutadiene with a quintuple-ζ basis set.

### A zeroth-order active-space frozen-orbital embedding scheme for multireference calculations.

- Computer Science, ChemistryThe Journal of chemical physics
- 2020

This work develops a zeroth-order active space embedding theory [ASET(0)], a simple and automatic approach for embedding any multireference dynamical correlation method based on a frozen-orbital treatment of the environment.

### A low-cost approach to electronic excitation energies based on the driven similarity renormalization group.

- Chemistry, PhysicsThe Journal of chemical physics
- 2017

Overall, VCIS-DS RG-PT2 yields results with accuracy comparable to those from time-dependent density functional theory using the B3LYP functional, while VCISD-DSRG- PT2 gives excitation energies comparable toThose from equation-of-motion coupled cluster with singles and doubles.

### Multireference Perturbation Theory with Cholesky Decomposition for the Density Matrix Renormalization Group

- PhysicsJournal of chemical theory and computation
- 2017

The accuracy of the strongly and partially contracted variant of CD-DMRG-NEVPT2 is assessed before embarking on resolving a controversy about the spin ground state of a cobalt tropocoronand complex.

### Second-Order Active-Space Embedding Theory.

- ChemistryJournal of chemical theory and computation
- 2022

Quantum embedding schemes are a promising way to extend multireference computations to large molecules with strong correlation effects localized on a small number of atoms. This work introduces a…

### Analytical Gradient Theory for Spin-Free State-Averaged Second-Order Driven Similarity Renormalization Group Perturbation Theory (SA-DSRG-MRPT2) and Its Applications for Conical Intersection Optimizations.

- PhysicsJournal of chemical theory and computation
- 2022

Second-order multireference-driven similarity renormalization group perturbation theory (DSRG-MRPT2) provides an efficient means of correcting the dynamical correlation with the multiconfiguration…

### A Combined Selected Configuration Interaction and Many-Body Treatment of Static and Dynamical Correlation in Oligoacenes.

- Physics, ChemistryJournal of chemical theory and computation
- 2018

Large bases and reference relaxation lead to a significant reduction in the estimated radical character of the oligoacenes, with respect to previous valence-only treatments of correlation effects.

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