Related Experiment Video
Updated: Oct 29, 2025

Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry
Published on: April 8, 2020
An efficient Fock space multi-reference coupled cluster method based on natural orbitals: Theory, implementation, and
Soumi Haldar1, Achintya Kumar Dutta1
1Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
Abstract:
We present a natural orbital-based implementation of the intermediate Hamiltonian Fock space coupled-cluster method for the (1, 1) sector of Fock space. The use of natural orbitals significantly reduces the computational cost and can automatically choose an appropriate set of active orbitals. The new method retains the charge transfer separability of the original intermediate Hamiltonian Fock space coupled-cluster method and gives excellent performance for valence, Rydberg, and charge-transfer excited states. It offers significant computational advantages over the popular equation of motion coupled cluster method for excited states dominated by single excitations.
Related Concept Videos
Hybridization of Atomic Orbitals II
Hybridization of Atomic Orbitals I
Molecular Orbital Theory I
Molecular Orbital Theory II
Atomic Orbitals
The Energies of Atomic Orbitals

