Exploring the Coexistence of Spin States in [Fe-(tpy-ph)$_2$]$^{2+}$ Complexes on Au(111) using ab initio calculations

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Dandu, Naveen K., Lee, Alex Taekyung, Ulloa, Sergio, Curtiss, Larry, Hla, Saw Wai, Ngo, Anh T.
Formato: Preprint
Publicado: 2024
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866914917955665920
author Dandu, Naveen K.
Lee, Alex Taekyung
Ulloa, Sergio
Curtiss, Larry
Hla, Saw Wai
Ngo, Anh T.
author_facet Dandu, Naveen K.
Lee, Alex Taekyung
Ulloa, Sergio
Curtiss, Larry
Hla, Saw Wai
Ngo, Anh T.
contents In this work, we systematically study the electronic structure and stability of spin states of the [Fe-(tpy-ph)$_2$]$^{2+}$ molecule in both gas phase and on a Au(111) substrate using density functional theory +U (DFT+U) calculations. We find that the stability of the Fe$^{2+}$ ion's spin states is significantly influenced by the Hubbard U parameter. In the gas phase, the low-spin (LS, S=0) state is found to be energetically favorable for U(Fe) $\leq$ 3 eV, whereas the high-spin (HS, S=2) state is stabilized for U(Fe) > 3 eV. Interaction with the Au(111) substrate is found to elevate the critical U for the spin-state transition to 3.5 eV. Additionally, we perform L-edge X-ray absorption spectroscopy (XAS) calculations based on time-dependent DFT (TD-DFT) for both HS and LS states. The calculated XAS suggests that the HS state more closely aligns with the experimental observations, indicating the potential coexistence of the HS state as the initial state during the X-ray excitation process. These findings enrich our understanding of spin-state dynamics in [Fe-(tpy-ph)$_2$]$^{2+}$.
format Preprint
id arxiv_https___arxiv_org_abs_2408_07014
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Exploring the Coexistence of Spin States in [Fe-(tpy-ph)$_2$]$^{2+}$ Complexes on Au(111) using ab initio calculations
Dandu, Naveen K.
Lee, Alex Taekyung
Ulloa, Sergio
Curtiss, Larry
Hla, Saw Wai
Ngo, Anh T.
Materials Science
Strongly Correlated Electrons
In this work, we systematically study the electronic structure and stability of spin states of the [Fe-(tpy-ph)$_2$]$^{2+}$ molecule in both gas phase and on a Au(111) substrate using density functional theory +U (DFT+U) calculations. We find that the stability of the Fe$^{2+}$ ion's spin states is significantly influenced by the Hubbard U parameter. In the gas phase, the low-spin (LS, S=0) state is found to be energetically favorable for U(Fe) $\leq$ 3 eV, whereas the high-spin (HS, S=2) state is stabilized for U(Fe) > 3 eV. Interaction with the Au(111) substrate is found to elevate the critical U for the spin-state transition to 3.5 eV. Additionally, we perform L-edge X-ray absorption spectroscopy (XAS) calculations based on time-dependent DFT (TD-DFT) for both HS and LS states. The calculated XAS suggests that the HS state more closely aligns with the experimental observations, indicating the potential coexistence of the HS state as the initial state during the X-ray excitation process. These findings enrich our understanding of spin-state dynamics in [Fe-(tpy-ph)$_2$]$^{2+}$.
title Exploring the Coexistence of Spin States in [Fe-(tpy-ph)$_2$]$^{2+}$ Complexes on Au(111) using ab initio calculations
topic Materials Science
Strongly Correlated Electrons
url https://arxiv.org/abs/2408.07014