24 citations · 50 across the 10 of their papers we have counts for
10 papers
Double Electron Attachment and Double Ionization Potential Equation-of-Motion Coupled-Cluster Approaches with Full and Active-Space Treatments of 4-Particle-2-Hole and 4-Hole-2-Particle Excitations and Three-Body Clusters
Jun Shen, Karthik Gururangan, Piotr Piecuch
The double electron attachment (DEA) and double ionization potential (DIP) equation-of-motion coupled-cluster (EOMCC) methods including up to 4-particle-2-hole (4-2) and 4-ho…
Extension of the CIPSI-Driven CC(;) Approach to Excited Electronic States
Swati S. Priyadarsini, Karthik Gururangan, Piotr Piecuch
We extend the CIPSI-driven CC(;) methodology [K. Gururangan et al., J. Chem. Phys. 155 (2021) 174114], in which the leading higher-than-doubly excited determinants are identi…
Reduced-Cost Four-Component Relativistic Double Ionization Potential Equation-of-Motion Coupled-Cluster Approaches with 4-Hole--2-Particle Excitations and Three-Body Clusters
Tamoghna Mukhopadhyay, Madhubani Mukherjee, Karthik Gururangan +2
The double ionization potential (DIP) equation-of-motion (EOM) coupled-cluster (CC) method with 4-hole--2-particle (4-2) excitations on top of the CC with singles, doubles, a…
Extension of the CC(;) Formalism to the Electron Attachment and Ionization Potential Equation-of-Motion Coupled-Cluster Frameworks
Karthik Gururangan, Stephen H. Yuwono, A. Eugene DePrince +1
We combine the electron attachment (EA) and ionization potential (IP) equation-of-motion (EOM) coupled-cluster (CC) approaches with the CC(;) formalism. The resulting methodo…
Double Ionization Potential Equation-of-Motion Coupled-Cluster Approach with Full Inclusion of 4-Hole-2-Particle Excitations and Three-Body Clusters
Karthik Gururangan, Achintya Kumar Dutta, Piotr Piecuch
The double ionization potential (DIP) equation-of-motion (EOM) coupled-cluster (CC) method with a full treatment of 4-hole-2-particle (4-2) correlations and triply excited cl…
Extension of the Active-Orbital-Based and Adaptive CC(;) Approaches to Excited Electronic States: Application to Potential Cuts of Water
Karthik Gururangan, Jun Shen, Piotr Piecuch
We report the first study using active-orbital-based and adaptive CC(;) approaches to describe excited electronic states. These CC(;) methodologies are applied, alongsi…
The Singlet-Triplet Gap of Cyclobutadiene: The CIPSI-Driven CC(;) Study
Swati S. Priyadarsini, Karthik Gururangan, Jun Shen +1
An accurate determination of singlet-triplet gaps in biradicals, including cyclobutadiene in the automerization barrier region where one has to balance the substantial nondynamical…
Converging High-Level Coupled-Cluster Energetics via Adaptive Selection of Excitation Manifolds Driven by Moment Expansions
Karthik Gururangan, Piotr Piecuch
A novel approach to rapidly converging high-level coupled-cluster (CC) energetics in an automated fashion is proposed. The key idea is an adaptive selection of the excitation manif…
High-Level Coupled-Cluster Energetics by Merging Moment Expansions with Selected Configuration Interaction
Karthik Gururangan, J. Emiliano Deustua, Jun Shen +1
Inspired by our earlier semi-stochastic work aimed at converging high-level coupled-cluster (CC) energetics [J. E. Deustua, J. Shen, and P. Piecuch, Phys. Rev. Lett. 119, 223003 (2…
Is Externally Corrected Coupled Cluster Always Better than the Underlying Truncated Configuration Interaction?
Ilias Magoulas, Karthik Gururangan, Piotr Piecuch +2
The short answer to the question in the title is 'no'. We identify classes of truncated configuration interaction (CI) wave functions for which the externally corrected coupled-clu…