Disjoint non-Kekule molecules are diradicals that present two independent radical centers and can violate Hund's rule, according to which the ground state should have triplet spin symmetry. The prototype of this class of systems is the tetramethyleneethane (TME) molecule for which indeed ion photoelectron spectroscopy (IPS) experiments revealed the singlet (1)A state to be more stable than the triplet B-3(u). In this work we investigate the potential energy curves of the two spin states of TME and of the two anionic states of TME- ((2)A and B-2(1)) as a function of the torsion of the central dihedral angle, with quantum Monte Carlo methods and a Jastrow Antisymmetrized Geminal Power wave function. Through ab initio geometrical optimizations we study the possible structural interconversions between the states, finding results which are in full agreement with the IPS experimental data.

Investigating Disjoint Non-Kekulé Diradicals with Quantum Monte Carlo: The Tetramethyleneethane Molecule through the Jastrow Antisymmetrized Geminal Power Wave Function

Coccia E
2015-01-01

Abstract

Disjoint non-Kekule molecules are diradicals that present two independent radical centers and can violate Hund's rule, according to which the ground state should have triplet spin symmetry. The prototype of this class of systems is the tetramethyleneethane (TME) molecule for which indeed ion photoelectron spectroscopy (IPS) experiments revealed the singlet (1)A state to be more stable than the triplet B-3(u). In this work we investigate the potential energy curves of the two spin states of TME and of the two anionic states of TME- ((2)A and B-2(1)) as a function of the torsion of the central dihedral angle, with quantum Monte Carlo methods and a Jastrow Antisymmetrized Geminal Power wave function. Through ab initio geometrical optimizations we study the possible structural interconversions between the states, finding results which are in full agreement with the IPS experimental data.
2015
Pubblicato
https://pubs.acs.org/doi/10.1021/acs.jctc.5b00819
File in questo prodotto:
File Dimensione Formato  
acs.jctc.5b00819.pdf

Accesso chiuso

Tipologia: Documento in Versione Editoriale
Licenza: Copyright Editore
Dimensione 1.59 MB
Formato Adobe PDF
1.59 MB Adobe PDF   Visualizza/Apri   Richiedi una copia
Pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11368/2938079
Citazioni
  • ???jsp.display-item.citation.pmc??? 1
  • Scopus 17
  • ???jsp.display-item.citation.isi??? 16
social impact