Intramolecular BSSE and dispersion affect the structure of a dipeptide conformer

Rabia Hameed; Afsar Khan; Tanja Van Mourik

doi:10.1080/00268976.2017.1418029

Intramolecular BSSE and dispersion affect the structure of a dipeptide conformer

Rabia Hameed, Afsar Khan, Tanja Van Mourik

Research output: Contribution to journal › Article › peer-review

Abstract

B3LYP and MP2 calculations with the commonly-used 6-31+G(d) basis set predict qualitatively different structures for the Tyr-Gly conformer book1, which is the most stable conformer identified in a previous study (Mol. Phys. 104, 559-570, 2006). The structures differ mainly in the ψ_Tyr Ramachandran angle (138° in the B3LYP structure and 120° in the MP2 structure). The causes for the discrepant structures are attributed to missing dispersion in the B3LYP calculations and large intramolecular BSSE in the MP2 calculations. The correct ψTyr value is estimated to be 130°. The MP2/6-31+G(d) profile identified an additional conformer, not present on the B3LYP surface, with a ψ_Tyr value of 96° and a more folded structure. This minimum is however likely an artefact of large intramolecular BSSE values. We recommend the use of basis sets of at least quadruple-zeta quality in DFT, DFT-D and MP2 calculations in cases where intramolecular BSSE is expected to be large.

Original language	English
Pages (from-to)	1236-1244
Number of pages	9
Journal	Molecular Physics
Volume	116
Issue number	9
Early online date	26 Dec 2017
DOIs	https://doi.org/10.1080/00268976.2017.1418029
Publication status	Published - 2018

Keywords

Tyrosine-glycine
Basis set superposition error
Density functional theory
MP2
DFT-D

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10.1080/00268976.2017.1418029

TvM_2017_MP_Dipeptideconformer_AAM
© 2017 Informa UK Limited, trading as Taylor & Francis Group. This work has been made available online in accordance with the publisher’s policies. This is the author created accepted version manuscript following peer review and as such may differ slightly from the final published version. The final published version of this work is available at https://doi.org/10.1080/00268976.2017.1418029
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@article{1c7799cd67b94344998e3b416de9a0a3,

title = "Intramolecular BSSE and dispersion affect the structure of a dipeptide conformer",

abstract = "B3LYP and MP2 calculations with the commonly-used 6-31+G(d) basis set predict qualitatively different structures for the Tyr-Gly conformer book1, which is the most stable conformer identified in a previous study (Mol. Phys. 104, 559-570, 2006). The structures differ mainly in the ψTyr Ramachandran angle (138° in the B3LYP structure and 120° in the MP2 structure). The causes for the discrepant structures are attributed to missing dispersion in the B3LYP calculations and large intramolecular BSSE in the MP2 calculations. The correct ψTyr value is estimated to be 130°. The MP2/6-31+G(d) profile identified an additional conformer, not present on the B3LYP surface, with a ψTyr value of 96° and a more folded structure. This minimum is however likely an artefact of large intramolecular BSSE values. We recommend the use of basis sets of at least quadruple-zeta quality in DFT, DFT-D and MP2 calculations in cases where intramolecular BSSE is expected to be large.",

keywords = "Tyrosine-glycine, Basis set superposition error, Density functional theory, MP2, DFT-D",

author = "Rabia Hameed and Afsar Khan and {Van Mourik}, Tanja",

note = "RH acknowledges funding from Higher Education Commission of Pakistan for her visit to the University of St Andrews as a visiting scholar.",

year = "2018",

doi = "10.1080/00268976.2017.1418029",

language = "English",

volume = "116",

pages = "1236--1244",

journal = "Molecular Physics",

issn = "0026-8976",

publisher = "Taylor and Francis",

number = "9",

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TY - JOUR

T1 - Intramolecular BSSE and dispersion affect the structure of a dipeptide conformer

AU - Hameed, Rabia

AU - Khan, Afsar

AU - Van Mourik, Tanja

N1 - RH acknowledges funding from Higher Education Commission of Pakistan for her visit to the University of St Andrews as a visiting scholar.

PY - 2018

Y1 - 2018

N2 - B3LYP and MP2 calculations with the commonly-used 6-31+G(d) basis set predict qualitatively different structures for the Tyr-Gly conformer book1, which is the most stable conformer identified in a previous study (Mol. Phys. 104, 559-570, 2006). The structures differ mainly in the ψTyr Ramachandran angle (138° in the B3LYP structure and 120° in the MP2 structure). The causes for the discrepant structures are attributed to missing dispersion in the B3LYP calculations and large intramolecular BSSE in the MP2 calculations. The correct ψTyr value is estimated to be 130°. The MP2/6-31+G(d) profile identified an additional conformer, not present on the B3LYP surface, with a ψTyr value of 96° and a more folded structure. This minimum is however likely an artefact of large intramolecular BSSE values. We recommend the use of basis sets of at least quadruple-zeta quality in DFT, DFT-D and MP2 calculations in cases where intramolecular BSSE is expected to be large.

AB - B3LYP and MP2 calculations with the commonly-used 6-31+G(d) basis set predict qualitatively different structures for the Tyr-Gly conformer book1, which is the most stable conformer identified in a previous study (Mol. Phys. 104, 559-570, 2006). The structures differ mainly in the ψTyr Ramachandran angle (138° in the B3LYP structure and 120° in the MP2 structure). The causes for the discrepant structures are attributed to missing dispersion in the B3LYP calculations and large intramolecular BSSE in the MP2 calculations. The correct ψTyr value is estimated to be 130°. The MP2/6-31+G(d) profile identified an additional conformer, not present on the B3LYP surface, with a ψTyr value of 96° and a more folded structure. This minimum is however likely an artefact of large intramolecular BSSE values. We recommend the use of basis sets of at least quadruple-zeta quality in DFT, DFT-D and MP2 calculations in cases where intramolecular BSSE is expected to be large.

KW - Tyrosine-glycine

KW - Basis set superposition error

KW - Density functional theory

KW - MP2

KW - DFT-D

U2 - 10.1080/00268976.2017.1418029

DO - 10.1080/00268976.2017.1418029

M3 - Article

SN - 0026-8976

VL - 116

SP - 1236

EP - 1244

JO - Molecular Physics

JF - Molecular Physics

IS - 9

ER -

Intramolecular BSSE and dispersion affect the structure of a dipeptide conformer

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Keywords

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