The relationship between structure and excited-state properties in polyanilines from geminal-based methods

Abstract

We employ state-of-the-art quantum chemistry methods to study the structure-to-property relationship in polyanilines (PANIs) of different lengths and oxidation states. Specifically, we focus on leucoemeraldine, emeraldine, and pernigraniline in their tetramer and octamer forms. We scrutinize their structural properties, HOMO and LUMO energies, HOMO-LUMO gaps, and vibrational and electronic spectroscopy using various Density Functional Approximations (DFAs). Furthermore, the accuracy of DFAs is assessed by comparing them to experimental and wavefunction-based reference data. We perform large-scale orbital-optimized pair-Coupled Cluster Doubles (oo-pCCD) calculations for ground and electronically excited states and conventional Configuration Interaction Singles (CIS) calculations for electronically excited states in all investigated systems. The EOM-pCCD+S approach with pCCD-optimized orbitals allows us to unambiguously identify charge transfer and local transitions across the investigated PANI systems -- an analysis not possible within a delocalized canonical molecular orbital basis obtained, for instance, by DFAs. We show that the low-lying part of the emeraldine and pernigraniline spectrum is dominated by charge transfer excitations and that polymer elongation changes the character of the leading transitions. Furthermore, we augment our study with a quantum informational analysis of orbital correlations in various forms of PANIs.

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References in corpus (9)

• Projected seniority-two orbital optimization of the Antisymmetric Product of one-reference orbital Geminal
• Targeting excited states in all-trans polyenes with electron-pair states
• Analysis of two-orbital correlations in wavefunctions restricted to electron-pair states
• Targeting doubly-excited states with Equation of Motion Coupled Cluster theory restricted to double excitations
• Pythonic Black-box Electronic Structure Tool (PyBEST). An open-source Python platform for electronic structure calculations at the interface between chemistry and physics
• Orbital entanglement and correlation from pCCD-tailored Coupled Cluster wave functions
• Assessing the accuracy of simplified Coupled Cluster methods for electronic excited states in f0 actinide compounds
• A configuration interaction correction on top of pair coupled cluster doubles
• Static Embedding with Pair Coupled Cluster Doubles Based Methods

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