activity
20242026
collaborators

7 papers

physics.chem-ph2026

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…

physics.chem-ph2026

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…

physics.chem-ph2025

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…

physics.chem-ph2025

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…

physics.chem-ph2025

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…

physics.chem-ph2025

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…