1. Four-component relativistic third-order algebraic diagrammatic construction theory for electron detachment, attachment, electronic excitation problem and calculation of first order transition properties
- Author
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Chakraborty, Sudipta, Mukhopadhyay, Tamoghna, Nayak, Malaya K., and Dutta, Achintya Kumar
- Subjects
Physics - Chemical Physics - Abstract
An efficient third-order algebraic diagrammatic construction (ADC) theory has been implemented to calculate ionisation potential, electron attachment and excitation energy (IP/EA/EE-ADC(3)) in a four-component relativistic framework. We have used polarisation propagator formulation for third-order perturbation theory to access the excitation energies (EE), and for IP/EA, a single-particle propagator has been used based on a non-Dyson formulation. The benchmarking calculations have been performed on various types of systems to test the accuracy of the four component ADC(3) scheme for the computation of IP, EA and EE. We have applied our IP-ADC(3) to demonstrate the computation of splitting in the IP states for halogen monoxides (XO, X = Cl, Br, I ) due to spin-orbital coupling in the 2^{\Pi} ground state and compared it with experimental results. Next, we have studied the effect of relativity and the size of the basis set on the electron attachment calculations of halogen atoms (F, Cl, Br, I and At) using EA-ADC(3). As our next step, we have shown the efficiency of four component ADC(3) in computing excitation energies of triiodide ion and compared with relativistic equation of motion coupled cluster with singles and doubles (EOM-CCSD), intermediate Hamiltonian Fock space coupled cluster (IHFS-CC) and other EOM-CCSD schemes in which spin-orbit coupling is incorporated with different degrees of approximation. Finally, we have also investigated the excitation energies and transition dipole moments for the four excited states of Xe atom and compared them with our recent four-component EOM-CCSD implementation and relativistic finite field Fock space coupled cluster results, along with the experimental estimates.
- Published
- 2024