Electronic structure and oxidation states in high-pressure synthesized isostructural CeCN$_5$ and TbCN$_5$

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Ehn, Amanda, Trybel, Florian, Masood, Talha Bin, Pourovskii, Leonid V., Abrikosov, Igor A.
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866918469037981696
author Ehn, Amanda
Trybel, Florian
Masood, Talha Bin
Pourovskii, Leonid V.
Abrikosov, Igor A.
author_facet Ehn, Amanda
Trybel, Florian
Masood, Talha Bin
Pourovskii, Leonid V.
Abrikosov, Igor A.
contents Understanding the behavior of 4$f$ electrons in materials containing rare earth elements is one of the fundamental questions within condensed matter physics. In this work the electronic properties of isostructural CeCN$_5$ and TbCN$_5$, both recently synthesized at extreme pressure, are investigated using Density Functional Theory (DFT) calculations. We include the on-site Coulomb repulsion between localized 4$f$ states within the static DFT+U framework; the DFT+U results are cross-checked with DFT+dynamical mean-field theory (DMFT) calculations within the quasi-atomic (Hubbard-I) approximation. Despite CeCN$_5$ and TbCN$_5$ being isostructural compounds Ce and Tb show different oxidation states, 4+ and 3+ respectively. This leads to distinctly different electronic properties: the former compound is an insulator, while the latter is a metal. An extra electron which is donated by Ce to the polymeric C-N network is distributed across the network. This leads to a modification of the bond length in CeCN$_5$ compared to TbCN$_5$. Still, the polymeric C-N networks can accommodate the different oxidation states in isostructural lanthanide-carbon-nitrogen (LnCN) compounds. Our results underline that LnCN compounds under high pressure offer a unique platform for probing the interplay between 4$f$-electron behavior and structural complexity.
format Preprint
id arxiv_https___arxiv_org_abs_2604_19629
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Electronic structure and oxidation states in high-pressure synthesized isostructural CeCN$_5$ and TbCN$_5$
Ehn, Amanda
Trybel, Florian
Masood, Talha Bin
Pourovskii, Leonid V.
Abrikosov, Igor A.
Materials Science
Strongly Correlated Electrons
Understanding the behavior of 4$f$ electrons in materials containing rare earth elements is one of the fundamental questions within condensed matter physics. In this work the electronic properties of isostructural CeCN$_5$ and TbCN$_5$, both recently synthesized at extreme pressure, are investigated using Density Functional Theory (DFT) calculations. We include the on-site Coulomb repulsion between localized 4$f$ states within the static DFT+U framework; the DFT+U results are cross-checked with DFT+dynamical mean-field theory (DMFT) calculations within the quasi-atomic (Hubbard-I) approximation. Despite CeCN$_5$ and TbCN$_5$ being isostructural compounds Ce and Tb show different oxidation states, 4+ and 3+ respectively. This leads to distinctly different electronic properties: the former compound is an insulator, while the latter is a metal. An extra electron which is donated by Ce to the polymeric C-N network is distributed across the network. This leads to a modification of the bond length in CeCN$_5$ compared to TbCN$_5$. Still, the polymeric C-N networks can accommodate the different oxidation states in isostructural lanthanide-carbon-nitrogen (LnCN) compounds. Our results underline that LnCN compounds under high pressure offer a unique platform for probing the interplay between 4$f$-electron behavior and structural complexity.
title Electronic structure and oxidation states in high-pressure synthesized isostructural CeCN$_5$ and TbCN$_5$
topic Materials Science
Strongly Correlated Electrons
url https://arxiv.org/abs/2604.19629