Energy bands and bond alternation potential in poly(para-phenylene vinylene)

A comparative ab initio quantum chemical and density functional theory study

Wolfgang Förner, F. Bogár, Reinhard Knab

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

We present calculations of the total energy per unit cell for different bond alternations of the C-C bonds bridging the distance between two aromatic rings in poly(para-phenylene vinylene) (PPV), using two different parametrizations of the energy functional in the local density approximation (LDA) and the ab initio Hartree-Fock (HF) method. For the application of correlation corrections to the HF results the system is already too large. We find that even simple LDA methods are reliable alternatives to the ab initio HF method for the calculation of potential surfaces in polymers with large unit cells. The results in turn can be used to determine parameters for model Hamiltonians necessary for theoretical studies of the dynamics of nonlinear quasiparticles in the polymers. We further present the LDA band structures of PPV together with their HF and correlation (many body perturbation theory of 2nd order in Møller-Plesset partitioning, MP2) corrected counterparts. We find that the fundamental gap obtained is too large both with HF and with the correlation corrected band structure compared to experiment. However, we use only a modest correlation method and a small basis set, which already brings us to the limits of the computers available to us. The LDA gaps on the other hand are too small which, however, could be corrected with the help of self interaction corrections. None of the latter methods would lead to exceedingly large computation times.

Original languageEnglish
Pages (from-to)73-84
Number of pages12
JournalJournal of Molecular Structure: THEOCHEM
Volume430
Issue number1-3
Publication statusPublished - Apr 14 1998

Fingerprint

Local density approximation
alternations
Band structure
Density functional theory
energy bands
density functional theory
approximation
Polymers
Hamiltonians
Correlation methods
polymers
Surface potential
cells
Nonlinear Dynamics
perturbation theory
Theoretical Models
poly-para-phenylene
energy
rings
Experiments

Keywords

  • Ab initio
  • DFT
  • Local density approximation
  • Poly(para-phenylene vinylene)

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Computational Theory and Mathematics
  • Atomic and Molecular Physics, and Optics

Cite this

@article{4495c07845944691ba29d82d6ab5184b,
title = "Energy bands and bond alternation potential in poly(para-phenylene vinylene): A comparative ab initio quantum chemical and density functional theory study",
abstract = "We present calculations of the total energy per unit cell for different bond alternations of the C-C bonds bridging the distance between two aromatic rings in poly(para-phenylene vinylene) (PPV), using two different parametrizations of the energy functional in the local density approximation (LDA) and the ab initio Hartree-Fock (HF) method. For the application of correlation corrections to the HF results the system is already too large. We find that even simple LDA methods are reliable alternatives to the ab initio HF method for the calculation of potential surfaces in polymers with large unit cells. The results in turn can be used to determine parameters for model Hamiltonians necessary for theoretical studies of the dynamics of nonlinear quasiparticles in the polymers. We further present the LDA band structures of PPV together with their HF and correlation (many body perturbation theory of 2nd order in M{\o}ller-Plesset partitioning, MP2) corrected counterparts. We find that the fundamental gap obtained is too large both with HF and with the correlation corrected band structure compared to experiment. However, we use only a modest correlation method and a small basis set, which already brings us to the limits of the computers available to us. The LDA gaps on the other hand are too small which, however, could be corrected with the help of self interaction corrections. None of the latter methods would lead to exceedingly large computation times.",
keywords = "Ab initio, DFT, Local density approximation, Poly(para-phenylene vinylene)",
author = "Wolfgang F{\"o}rner and F. Bog{\'a}r and Reinhard Knab",
year = "1998",
month = "4",
day = "14",
language = "English",
volume = "430",
pages = "73--84",
journal = "Computational and Theoretical Chemistry",
issn = "2210-271X",
publisher = "Elsevier BV",
number = "1-3",

}

TY - JOUR

T1 - Energy bands and bond alternation potential in poly(para-phenylene vinylene)

T2 - A comparative ab initio quantum chemical and density functional theory study

AU - Förner, Wolfgang

AU - Bogár, F.

AU - Knab, Reinhard

PY - 1998/4/14

Y1 - 1998/4/14

N2 - We present calculations of the total energy per unit cell for different bond alternations of the C-C bonds bridging the distance between two aromatic rings in poly(para-phenylene vinylene) (PPV), using two different parametrizations of the energy functional in the local density approximation (LDA) and the ab initio Hartree-Fock (HF) method. For the application of correlation corrections to the HF results the system is already too large. We find that even simple LDA methods are reliable alternatives to the ab initio HF method for the calculation of potential surfaces in polymers with large unit cells. The results in turn can be used to determine parameters for model Hamiltonians necessary for theoretical studies of the dynamics of nonlinear quasiparticles in the polymers. We further present the LDA band structures of PPV together with their HF and correlation (many body perturbation theory of 2nd order in Møller-Plesset partitioning, MP2) corrected counterparts. We find that the fundamental gap obtained is too large both with HF and with the correlation corrected band structure compared to experiment. However, we use only a modest correlation method and a small basis set, which already brings us to the limits of the computers available to us. The LDA gaps on the other hand are too small which, however, could be corrected with the help of self interaction corrections. None of the latter methods would lead to exceedingly large computation times.

AB - We present calculations of the total energy per unit cell for different bond alternations of the C-C bonds bridging the distance between two aromatic rings in poly(para-phenylene vinylene) (PPV), using two different parametrizations of the energy functional in the local density approximation (LDA) and the ab initio Hartree-Fock (HF) method. For the application of correlation corrections to the HF results the system is already too large. We find that even simple LDA methods are reliable alternatives to the ab initio HF method for the calculation of potential surfaces in polymers with large unit cells. The results in turn can be used to determine parameters for model Hamiltonians necessary for theoretical studies of the dynamics of nonlinear quasiparticles in the polymers. We further present the LDA band structures of PPV together with their HF and correlation (many body perturbation theory of 2nd order in Møller-Plesset partitioning, MP2) corrected counterparts. We find that the fundamental gap obtained is too large both with HF and with the correlation corrected band structure compared to experiment. However, we use only a modest correlation method and a small basis set, which already brings us to the limits of the computers available to us. The LDA gaps on the other hand are too small which, however, could be corrected with the help of self interaction corrections. None of the latter methods would lead to exceedingly large computation times.

KW - Ab initio

KW - DFT

KW - Local density approximation

KW - Poly(para-phenylene vinylene)

UR - http://www.scopus.com/inward/record.url?scp=0038309686&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0038309686&partnerID=8YFLogxK

M3 - Article

VL - 430

SP - 73

EP - 84

JO - Computational and Theoretical Chemistry

JF - Computational and Theoretical Chemistry

SN - 2210-271X

IS - 1-3

ER -