New Insight into the Ground State of FePc: A Diffusion Monte Carlo Study

• Ichibha, Tom

• Hou, Zhufeng

• Hongo, Kenta

• Maezono, Ryo

Abstract

We have applied DMC to evaluate relative stability of the possible electronic configurations of an isolated FePc under D_<4h> symmetry, considering some fixed nodes generated from different methods. They predict A_<2g> ground state consistently, supporting preceding DFT studies, with confidence overcoming the ambiguity about exchange-correlation (XC) functionals. By comparing DMC with several XC, we clarified the importance of the short-range exchange to describe the relative stability. We examined why the predicted A_<2g> is excluded from possible ground states in the recent ligand field based model. Simplified assumptions made in the superposition model are identified to give unreasonably less energy gain for A_<2g> when compared with the reality. The state is found to have possible reasons for the stabilization, reducing the occupations from an unstable anti-bonding orbital, avoiding double occupation of a spatially localized orbital, and gaining exchange energy by putting a triplet spin pair in degenerate orbitals.

identifier:https://dspace.jaist.ac.jp/dspace/handle/10119/15358

Journal

• Scientific Reports

  Scientific Reports 7 Article number: 2011-, 2017-05-17

  Springer Nature

Keywords

• Quantum Monte Carlo
• DFT
• Iron(II) Phthalocyanine
• Excited states

Details

• CRID: 1050282812515258368
• NII Article ID: 120006490001
• ISSN: 20452322
• DOI: 10.1038/s41598-017-01668-6
• Web Site: http://hdl.handle.net/10119/15358
• Web Site: https://www.nature.com/articles/s41598-017-01668-6.pdf
• Web Site: https://www.nature.com/articles/s41598-017-01668-6
• Text Lang: en
• Article Type: journal article
• Data Source:
  • IRDB
  • Crossref
  • CiNii Articles
  • KAKEN