Size-extensive Corrected Configuration interaction potential energy curves for the ground and excited states of some diatomic molecules

Ertürk M.

Türk Fizik Derneği 37. Uluslararası Fizik Kongresi, Muğla, Turkey, 1 - 05 September 2021, pp.84

  • Publication Type: Conference Paper / Summary Text
  • City: Muğla
  • Country: Turkey
  • Page Numbers: pp.84
  • Çanakkale Onsekiz Mart University Affiliated: Yes

Abstract

We have performed various size-extensivity corrections [1-3] to discuss a few examples illustrating the performance of the Coupled-Cluster correction approaches in the calculations of the excited-state of some diatomic molecules. It is shown that the coupled-cluster corrections with noniterative evaluation of connected triples are much better and reliable approximation to the SR- and MR-CISD energy than other correction methods proposed. The SR-CISD, SR-CCSD, SOCI and FCI results have been calculated using the GAMESS program package. Hartree-Fock method is employed to generate molecular orbitals and the HF determinant is selected as the reference in all calculations. All energies given in tables are presented relative to the FCI energies (in mH).

 

[1] L. Meissner, Chem. Phys. Lett. 263 (1996) 351.

[2] L. Meissner, Int. J. Quantum Chem. 108 (2008) 2199.

 [3] M. Erturk, L. Meissner, Mol. Phys. 113 (2015) 3014.