---
_id: '64071'
abstract:
- lang: eng
  text: Stimulated by the renewed interest and recent developments in semi-empirical
    quantum chemical (SQC) methods for noncovalent interactions, we examine the properties
    of liquid water at ambient conditions by means of molecular dynamics (MD) simulations,
    both with the conventional NDDO-type (neglect of diatomic differential overlap)
    methods, e.g. AM1 and PM6, and with DFTB-type (density-functional tight-binding)
    methods, e.g. DFTB2 and GFN-xTB. Besides the original parameter sets, some specifically
    reparametrized SQC methods (denoted as AM1-W, PM6-fm, and DFTB2-iBi) targeting
    various smaller water systems ranging from molecular clusters to bulk are considered
    as well. The quality of these different SQC methods for describing liquid water
    properties at ambient conditions are assessed by comparison to well-established
    experimental data and also to BLYP-D3 density functional theory-based ab initio
    MD simulations. Our analyses reveal that static and dynamics properties of bulk
    water are poorly described by all considered SQC methods with the original parameters,
    regardless of the underlying theoretical models, with most of the methods suffering
    from too weak hydrogen bonds and hence predicting a far too fluid water with highly
    distorted hydrogen bond kinetics. On the other hand, the reparametrized force-matchcd
    PM6-fm method is shown to be able to quantitatively reproduce the static and dynamic
    features of liquid water, and thus can be used as a computationally efficient
    alternative to electronic structure-based MD simulations for liquid water that
    requires extended length and time scales. DFTB2-iBi predicts a slightly overstructured
    water with reduced fluidity, whereas AM1-W gives an amorphous ice-like structure
    for water at ambient conditions.
author:
- first_name: Xin
  full_name: Wu, Xin
  id: '77439'
  last_name: Wu
- first_name: Hossam
  full_name: Elgabarty, Hossam
  id: '60250'
  last_name: Elgabarty
  orcid: 0000-0002-4945-1481
- first_name: Vahideh
  full_name: Alizadeh, Vahideh
  last_name: Alizadeh
- first_name: Andres
  full_name: Henao Aristizabal, Andres
  id: '67235'
  last_name: Henao Aristizabal
- first_name: Frederik
  full_name: Zysk, Frederik
  id: '14757'
  last_name: Zysk
- first_name: Christian
  full_name: Plessl, Christian
  id: '16153'
  last_name: Plessl
  orcid: 0000-0001-5728-9982
- first_name: Sebastian
  full_name: Ehlert, Sebastian
  last_name: Ehlert
- first_name: Jürg
  full_name: Hutter, Jürg
  last_name: Hutter
- first_name: Thomas D.
  full_name: Kühne, Thomas D.
  id: '49079'
  last_name: Kühne
citation:
  ama: Wu X, Elgabarty H, Alizadeh V, et al. Benchmarking semi-empirical quantum chemical
    methods on liquid water. Published online 2025.
  apa: Wu, X., Elgabarty, H., Alizadeh, V., Henao Aristizabal, A., Zysk, F., Plessl,
    C., Ehlert, S., Hutter, J., &#38; Kühne, T. D. (2025). <i>Benchmarking semi-empirical
    quantum chemical methods on liquid water</i>.
  bibtex: '@article{Wu_Elgabarty_Alizadeh_Henao Aristizabal_Zysk_Plessl_Ehlert_Hutter_Kühne_2025,
    title={Benchmarking semi-empirical quantum chemical methods on liquid water},
    author={Wu, Xin and Elgabarty, Hossam and Alizadeh, Vahideh and Henao Aristizabal,
    Andres and Zysk, Frederik and Plessl, Christian and Ehlert, Sebastian and Hutter,
    Jürg and Kühne, Thomas D.}, year={2025} }'
  chicago: Wu, Xin, Hossam Elgabarty, Vahideh Alizadeh, Andres Henao Aristizabal,
    Frederik Zysk, Christian Plessl, Sebastian Ehlert, Jürg Hutter, and Thomas D.
    Kühne. “Benchmarking Semi-Empirical Quantum Chemical Methods on Liquid Water,”
    2025.
  ieee: X. Wu <i>et al.</i>, “Benchmarking semi-empirical quantum chemical methods
    on liquid water.” 2025.
  mla: Wu, Xin, et al. <i>Benchmarking Semi-Empirical Quantum Chemical Methods on
    Liquid Water</i>. 2025.
  short: X. Wu, H. Elgabarty, V. Alizadeh, A. Henao Aristizabal, F. Zysk, C. Plessl,
    S. Ehlert, J. Hutter, T.D. Kühne, (2025).
date_created: 2026-02-09T09:03:41Z
date_updated: 2026-02-09T09:17:07Z
department:
- _id: '27'
- _id: '2'
language:
- iso: eng
main_file_link:
- url: https://arxiv.org/abs/2503.11867
project:
- _id: '52'
  name: Computing Resources Provided by the Paderborn Center for Parallel Computing
status: public
title: Benchmarking semi-empirical quantum chemical methods on liquid water
type: preprint
user_id: '77439'
year: '2025'
...
---
_id: '33678'
abstract:
- lang: eng
  text: '<jats:p>Accelerated chemistry at the interface with water has received increasing
    attention. The mechanisms behind the enhanced reactivity On-Water are not yet
    clear. In this work we use a Langevin scheme in the spirit of second generation
    Car-Parrinello to accelerate the second-order density functional Tight-Binding
    (DFTB2) method in order to investigate the free energy of two Diels-Alder reaction
    On-Water: the cycloaddition between cyclopentadiene and ethyl cinnamate or thionocinnamate.
    The only difference between the reactants is the substitution of a carbonyl oxygen
    for a thiocarbonyl sulfur, making possible the distinction between them as strong
    and weak hydrogen-bond acceptors. We find a different mechanism for the reaction
    during the transition states and uncover the role of hydrogen bonds along with
    the reaction path. Our results suggest that acceleration of Diels-Alder reactions
    do not arise from an increased number of hydrogen bonds at the transition state
    and charge transfer plays a significant role. However, the presence of water and
    hydrogen-bonds is determinant for the catalysis of these reactions.</jats:p>'
author:
- first_name: Andres
  full_name: Henao Aristizabal, Andres
  id: '67235'
  last_name: Henao Aristizabal
- first_name: Yomna
  full_name: Gohar, Yomna
  last_name: Gohar
- first_name: René
  full_name: Whilhelm, René
  last_name: Whilhelm
- first_name: Thomas
  full_name: Kühne, Thomas
  id: '49079'
  last_name: Kühne
citation:
  ama: 'Henao Aristizabal A, Gohar Y, Whilhelm R, Kühne T. On the Role of Hydrogen
    Bond Strength and Charge Transfer of a Diels-Alder Reaction On-Water: Semiempirical
    and Free Energy Calculations. Published online 2022.'
  apa: 'Henao Aristizabal, A., Gohar, Y., Whilhelm, R., &#38; Kühne, T. (2022). <i>On
    the Role of Hydrogen Bond Strength and Charge Transfer of a Diels-Alder Reaction
    On-Water: Semiempirical and Free Energy Calculations.</i> American Chemical Society
    (ACS).'
  bibtex: '@article{Henao Aristizabal_Gohar_Whilhelm_Kühne_2022, title={On the Role
    of Hydrogen Bond Strength and Charge Transfer of a Diels-Alder Reaction On-Water:
    Semiempirical and Free Energy Calculations.}, publisher={American Chemical Society
    (ACS)}, author={Henao Aristizabal, Andres and Gohar, Yomna and Whilhelm, René
    and Kühne, Thomas}, year={2022} }'
  chicago: 'Henao Aristizabal, Andres, Yomna Gohar, René Whilhelm, and Thomas Kühne.
    “On the Role of Hydrogen Bond Strength and Charge Transfer of a Diels-Alder Reaction
    On-Water: Semiempirical and Free Energy Calculations.” American Chemical Society
    (ACS), 2022.'
  ieee: 'A. Henao Aristizabal, Y. Gohar, R. Whilhelm, and T. Kühne, “On the Role of
    Hydrogen Bond Strength and Charge Transfer of a Diels-Alder Reaction On-Water:
    Semiempirical and Free Energy Calculations.” American Chemical Society (ACS),
    2022.'
  mla: 'Henao Aristizabal, Andres, et al. <i>On the Role of Hydrogen Bond Strength
    and Charge Transfer of a Diels-Alder Reaction On-Water: Semiempirical and Free
    Energy Calculations.</i> American Chemical Society (ACS), 2022.'
  short: A. Henao Aristizabal, Y. Gohar, R. Whilhelm, T. Kühne, (2022).
date_created: 2022-10-11T08:11:10Z
date_updated: 2022-10-11T08:11:23Z
department:
- _id: '613'
language:
- iso: eng
publication_status: published
publisher: American Chemical Society (ACS)
status: public
title: 'On the Role of Hydrogen Bond Strength and Charge Transfer of a Diels-Alder
  Reaction On-Water: Semiempirical and Free Energy Calculations.'
type: preprint
user_id: '71051'
year: '2022'
...