---
_id: '63223'
abstract:
- lang: eng
  text: <jats:title>Abstract</jats:title><jats:p>The quartz crystal microbalance with
    dissipation monitoring (QCM‐D) is routinely used to investigate structured samples.
    Here, a simulation technique is described, that predicts the shifts of frequency
    and half bandwidth, Δ<jats:italic>f<jats:sub>n</jats:sub></jats:italic> and ΔΓ<jats:italic><jats:sub>n</jats:sub></jats:italic>,
    of a quartz resonator operating on different overtone orders, <jats:italic>n</jats:italic>,
    induced by structured samples in contact with the resonator surface in liquid.
    The technique, abbreviated as FreqD‐LBM, solves the Stokes equation in the frequency
    domain. The solution provides the complex amplitude of the area‐averaged tangential
    stress at the resonator surface, from which Δ<jats:italic>f<jats:sub>n</jats:sub></jats:italic>
    and ΔΓ<jats:italic><jats:sub>n</jats:sub></jats:italic> are derived. Because the
    dynamical variables are complex amplitudes, the viscosity can be complex, as well.
    The technique naturally covers viscoelasticity. Limitations are linked to the
    grid resolution and to problems at large viscosity. Validation steps include viscoelastic
    films, rough surfaces, an oscillating cylinder in a viscous medium, and a free‐floating
    sphere above the resonator. Application examples are soft adsorbed particles,
    stiff adsorbed particles, and a large, immobile spherical cap above the resonator,
    which allows to study the high‐frequency properties of the material in the gap.
    FreqDLBM runs on an office PC and does not require expert knowledge of numerical
    techniques. It is accessible to an experimentalist.</jats:p>
article_number: '2401373'
article_type: original
author:
- first_name: Diethelm
  full_name: Johannsmann, Diethelm
  last_name: Johannsmann
- first_name: Paul
  full_name: Häusner, Paul
  last_name: Häusner
- first_name: Arne
  full_name: Langhoff, Arne
  last_name: Langhoff
- first_name: Christian
  full_name: Leppin, Christian
  id: '117722'
  last_name: Leppin
- first_name: Ilya
  full_name: Reviakine, Ilya
  last_name: Reviakine
- first_name: Viktor
  full_name: Vanoppen, Viktor
  last_name: Vanoppen
citation:
  ama: 'Johannsmann D, Häusner P, Langhoff A, Leppin C, Reviakine I, Vanoppen V. The
    Frequency‐Domain Lattice Boltzmann Method (FreqD‐LBM): A Versatile Tool to Predict
    the QCM Response Induced by Structured Samples. <i>Advanced Theory and Simulations</i>.
    2025;8(7). doi:<a href="https://doi.org/10.1002/adts.202401373">10.1002/adts.202401373</a>'
  apa: 'Johannsmann, D., Häusner, P., Langhoff, A., Leppin, C., Reviakine, I., &#38;
    Vanoppen, V. (2025). The Frequency‐Domain Lattice Boltzmann Method (FreqD‐LBM):
    A Versatile Tool to Predict the QCM Response Induced by Structured Samples. <i>Advanced
    Theory and Simulations</i>, <i>8</i>(7), Article 2401373. <a href="https://doi.org/10.1002/adts.202401373">https://doi.org/10.1002/adts.202401373</a>'
  bibtex: '@article{Johannsmann_Häusner_Langhoff_Leppin_Reviakine_Vanoppen_2025, title={The
    Frequency‐Domain Lattice Boltzmann Method (FreqD‐LBM): A Versatile Tool to Predict
    the QCM Response Induced by Structured Samples}, volume={8}, DOI={<a href="https://doi.org/10.1002/adts.202401373">10.1002/adts.202401373</a>},
    number={72401373}, journal={Advanced Theory and Simulations}, publisher={Wiley},
    author={Johannsmann, Diethelm and Häusner, Paul and Langhoff, Arne and Leppin,
    Christian and Reviakine, Ilya and Vanoppen, Viktor}, year={2025} }'
  chicago: 'Johannsmann, Diethelm, Paul Häusner, Arne Langhoff, Christian Leppin,
    Ilya Reviakine, and Viktor Vanoppen. “The Frequency‐Domain Lattice Boltzmann Method
    (FreqD‐LBM): A Versatile Tool to Predict the QCM Response Induced by Structured
    Samples.” <i>Advanced Theory and Simulations</i> 8, no. 7 (2025). <a href="https://doi.org/10.1002/adts.202401373">https://doi.org/10.1002/adts.202401373</a>.'
  ieee: 'D. Johannsmann, P. Häusner, A. Langhoff, C. Leppin, I. Reviakine, and V.
    Vanoppen, “The Frequency‐Domain Lattice Boltzmann Method (FreqD‐LBM): A Versatile
    Tool to Predict the QCM Response Induced by Structured Samples,” <i>Advanced Theory
    and Simulations</i>, vol. 8, no. 7, Art. no. 2401373, 2025, doi: <a href="https://doi.org/10.1002/adts.202401373">10.1002/adts.202401373</a>.'
  mla: 'Johannsmann, Diethelm, et al. “The Frequency‐Domain Lattice Boltzmann Method
    (FreqD‐LBM): A Versatile Tool to Predict the QCM Response Induced by Structured
    Samples.” <i>Advanced Theory and Simulations</i>, vol. 8, no. 7, 2401373, Wiley,
    2025, doi:<a href="https://doi.org/10.1002/adts.202401373">10.1002/adts.202401373</a>.'
  short: D. Johannsmann, P. Häusner, A. Langhoff, C. Leppin, I. Reviakine, V. Vanoppen,
    Advanced Theory and Simulations 8 (2025).
date_created: 2025-12-18T16:57:22Z
date_updated: 2025-12-18T17:46:34Z
doi: 10.1002/adts.202401373
intvolume: '         8'
issue: '7'
language:
- iso: eng
publication: Advanced Theory and Simulations
publication_identifier:
  issn:
  - 2513-0390
  - 2513-0390
publication_status: published
publisher: Wiley
quality_controlled: '1'
status: public
title: 'The Frequency‐Domain Lattice Boltzmann Method (FreqD‐LBM): A Versatile Tool
  to Predict the QCM Response Induced by Structured Samples'
type: journal_article
user_id: '117722'
volume: 8
year: '2025'
...
---
_id: '63228'
abstract:
- lang: eng
  text: <jats:title>Abstract</jats:title><jats:p>A simulation based on the frequency‐domain
    lattice Boltzmann method (FreqD‐LBM) is employed to predict the shifts of resonance
    frequency, Δ<jats:italic>f</jats:italic>, and half bandwidth, ΔΓ, of a quartz
    crystal microbalance with dissipation monitoring (QCM‐D) induced by the adsorption
    of rigid spheres to the resonator surface. The comparison with the experimental
    values of Δ<jats:italic>f</jats:italic> and ΔΓ allows to estimate the stiffness
    of the contacts between the spheres and the resonator surface. The contact stiffness
    is of interest in contact mechanics, but also in sensing because it depends on
    the properties of thin films situated between the resonator surface and the sphere.
    The simulation differs from previous implementations of FreqD‐LBM insofar, as
    the material inside the particles is not included in the FreqD‐LBM algorithm.
    Rather, the particle surface is configured to be an oscillating boundary. The
    amplitude of the particles' motions (displacement and rotation) is governed by
    the force balance at the surface of the particle. Because the contact stiffness
    enters this balance, it can be derived from experimental values of Δ<jats:italic>f</jats:italic>
    and ΔΓ. The simulation reproduces experiments by the Krakow group. For sufficiently
    small spheres, a contact stiffness can be derived from the comparison of the simulation
    with the experiment.</jats:p>
article_number: '2300190'
article_type: original
author:
- first_name: Diethelm
  full_name: Johannsmann, Diethelm
  last_name: Johannsmann
- first_name: Christian
  full_name: Leppin, Christian
  id: '117722'
  last_name: Leppin
- first_name: Arne
  full_name: Langhoff, Arne
  last_name: Langhoff
citation:
  ama: Johannsmann D, Leppin C, Langhoff A. Stiffness of Contacts between Adsorbed
    Particles and the Surface of a QCM‐D Inferred from the Adsorption Kinetics and
    a Frequency‐Domain Lattice Boltzmann Simulation. <i>Advanced Theory and Simulations</i>.
    2023;6(11). doi:<a href="https://doi.org/10.1002/adts.202300190">10.1002/adts.202300190</a>
  apa: Johannsmann, D., Leppin, C., &#38; Langhoff, A. (2023). Stiffness of Contacts
    between Adsorbed Particles and the Surface of a QCM‐D Inferred from the Adsorption
    Kinetics and a Frequency‐Domain Lattice Boltzmann Simulation. <i>Advanced Theory
    and Simulations</i>, <i>6</i>(11), Article 2300190. <a href="https://doi.org/10.1002/adts.202300190">https://doi.org/10.1002/adts.202300190</a>
  bibtex: '@article{Johannsmann_Leppin_Langhoff_2023, title={Stiffness of Contacts
    between Adsorbed Particles and the Surface of a QCM‐D Inferred from the Adsorption
    Kinetics and a Frequency‐Domain Lattice Boltzmann Simulation}, volume={6}, DOI={<a
    href="https://doi.org/10.1002/adts.202300190">10.1002/adts.202300190</a>}, number={112300190},
    journal={Advanced Theory and Simulations}, publisher={Wiley}, author={Johannsmann,
    Diethelm and Leppin, Christian and Langhoff, Arne}, year={2023} }'
  chicago: Johannsmann, Diethelm, Christian Leppin, and Arne Langhoff. “Stiffness
    of Contacts between Adsorbed Particles and the Surface of a QCM‐D Inferred from
    the Adsorption Kinetics and a Frequency‐Domain Lattice Boltzmann Simulation.”
    <i>Advanced Theory and Simulations</i> 6, no. 11 (2023). <a href="https://doi.org/10.1002/adts.202300190">https://doi.org/10.1002/adts.202300190</a>.
  ieee: 'D. Johannsmann, C. Leppin, and A. Langhoff, “Stiffness of Contacts between
    Adsorbed Particles and the Surface of a QCM‐D Inferred from the Adsorption Kinetics
    and a Frequency‐Domain Lattice Boltzmann Simulation,” <i>Advanced Theory and Simulations</i>,
    vol. 6, no. 11, Art. no. 2300190, 2023, doi: <a href="https://doi.org/10.1002/adts.202300190">10.1002/adts.202300190</a>.'
  mla: Johannsmann, Diethelm, et al. “Stiffness of Contacts between Adsorbed Particles
    and the Surface of a QCM‐D Inferred from the Adsorption Kinetics and a Frequency‐Domain
    Lattice Boltzmann Simulation.” <i>Advanced Theory and Simulations</i>, vol. 6,
    no. 11, 2300190, Wiley, 2023, doi:<a href="https://doi.org/10.1002/adts.202300190">10.1002/adts.202300190</a>.
  short: D. Johannsmann, C. Leppin, A. Langhoff, Advanced Theory and Simulations 6
    (2023).
date_created: 2025-12-18T17:03:12Z
date_updated: 2025-12-18T17:41:08Z
doi: 10.1002/adts.202300190
extern: '1'
intvolume: '         6'
issue: '11'
language:
- iso: eng
publication: Advanced Theory and Simulations
publication_identifier:
  issn:
  - 2513-0390
  - 2513-0390
publication_status: published
publisher: Wiley
quality_controlled: '1'
status: public
title: Stiffness of Contacts between Adsorbed Particles and the Surface of a QCM‐D
  Inferred from the Adsorption Kinetics and a Frequency‐Domain Lattice Boltzmann Simulation
type: journal_article
user_id: '117722'
volume: 6
year: '2023'
...
---
_id: '23598'
article_number: '2000269'
author:
- first_name: Jan
  full_name: Kessler, Jan
  last_name: Kessler
- first_name: Francesco
  full_name: Calcavecchia, Francesco
  last_name: Calcavecchia
- first_name: Thomas D.
  full_name: Kühne, Thomas D.
  last_name: Kühne
citation:
  ama: Kessler J, Calcavecchia F, Kühne TD. Artificial Neural Networks as Trial Wave
    Functions for Quantum Monte Carlo. <i>Advanced Theory and Simulations</i>. 2021.
    doi:<a href="https://doi.org/10.1002/adts.202000269">10.1002/adts.202000269</a>
  apa: Kessler, J., Calcavecchia, F., &#38; Kühne, T. D. (2021). Artificial Neural
    Networks as Trial Wave Functions for Quantum Monte Carlo. <i>Advanced Theory and
    Simulations</i>. <a href="https://doi.org/10.1002/adts.202000269">https://doi.org/10.1002/adts.202000269</a>
  bibtex: '@article{Kessler_Calcavecchia_Kühne_2021, title={Artificial Neural Networks
    as Trial Wave Functions for Quantum Monte Carlo}, DOI={<a href="https://doi.org/10.1002/adts.202000269">10.1002/adts.202000269</a>},
    number={2000269}, journal={Advanced Theory and Simulations}, author={Kessler,
    Jan and Calcavecchia, Francesco and Kühne, Thomas D.}, year={2021} }'
  chicago: Kessler, Jan, Francesco Calcavecchia, and Thomas D. Kühne. “Artificial
    Neural Networks as Trial Wave Functions for Quantum Monte Carlo.” <i>Advanced
    Theory and Simulations</i>, 2021. <a href="https://doi.org/10.1002/adts.202000269">https://doi.org/10.1002/adts.202000269</a>.
  ieee: J. Kessler, F. Calcavecchia, and T. D. Kühne, “Artificial Neural Networks
    as Trial Wave Functions for Quantum Monte Carlo,” <i>Advanced Theory and Simulations</i>,
    2021.
  mla: Kessler, Jan, et al. “Artificial Neural Networks as Trial Wave Functions for
    Quantum Monte Carlo.” <i>Advanced Theory and Simulations</i>, 2000269, 2021, doi:<a
    href="https://doi.org/10.1002/adts.202000269">10.1002/adts.202000269</a>.
  short: J. Kessler, F. Calcavecchia, T.D. Kühne, Advanced Theory and Simulations
    (2021).
date_created: 2021-09-01T09:04:06Z
date_updated: 2022-01-06T06:55:57Z
doi: 10.1002/adts.202000269
language:
- iso: eng
publication: Advanced Theory and Simulations
publication_identifier:
  issn:
  - 2513-0390
  - 2513-0390
publication_status: published
status: public
title: Artificial Neural Networks as Trial Wave Functions for Quantum Monte Carlo
type: journal_article
user_id: '65425'
year: '2021'
...
---
_id: '33649'
article_number: '2000269'
author:
- first_name: Jan
  full_name: Kessler, Jan
  id: '65425'
  last_name: Kessler
  orcid: 0000-0002-8705-6992
- first_name: Francesco
  full_name: Calcavecchia, Francesco
  last_name: Calcavecchia
- first_name: Thomas
  full_name: Kühne, Thomas
  id: '49079'
  last_name: Kühne
citation:
  ama: Kessler J, Calcavecchia F, Kühne T. Artificial Neural Networks as Trial Wave
    Functions for Quantum Monte Carlo. <i>Advanced Theory and Simulations</i>. 2021;4(4).
    doi:<a href="https://doi.org/10.1002/adts.202000269">10.1002/adts.202000269</a>
  apa: Kessler, J., Calcavecchia, F., &#38; Kühne, T. (2021). Artificial Neural Networks
    as Trial Wave Functions for Quantum Monte Carlo. <i>Advanced Theory and Simulations</i>,
    <i>4</i>(4), Article 2000269. <a href="https://doi.org/10.1002/adts.202000269">https://doi.org/10.1002/adts.202000269</a>
  bibtex: '@article{Kessler_Calcavecchia_Kühne_2021, title={Artificial Neural Networks
    as Trial Wave Functions for Quantum Monte Carlo}, volume={4}, DOI={<a href="https://doi.org/10.1002/adts.202000269">10.1002/adts.202000269</a>},
    number={42000269}, journal={Advanced Theory and Simulations}, publisher={Wiley},
    author={Kessler, Jan and Calcavecchia, Francesco and Kühne, Thomas}, year={2021}
    }'
  chicago: Kessler, Jan, Francesco Calcavecchia, and Thomas Kühne. “Artificial Neural
    Networks as Trial Wave Functions for Quantum Monte Carlo.” <i>Advanced Theory
    and Simulations</i> 4, no. 4 (2021). <a href="https://doi.org/10.1002/adts.202000269">https://doi.org/10.1002/adts.202000269</a>.
  ieee: 'J. Kessler, F. Calcavecchia, and T. Kühne, “Artificial Neural Networks as
    Trial Wave Functions for Quantum Monte Carlo,” <i>Advanced Theory and Simulations</i>,
    vol. 4, no. 4, Art. no. 2000269, 2021, doi: <a href="https://doi.org/10.1002/adts.202000269">10.1002/adts.202000269</a>.'
  mla: Kessler, Jan, et al. “Artificial Neural Networks as Trial Wave Functions for
    Quantum Monte Carlo.” <i>Advanced Theory and Simulations</i>, vol. 4, no. 4, 2000269,
    Wiley, 2021, doi:<a href="https://doi.org/10.1002/adts.202000269">10.1002/adts.202000269</a>.
  short: J. Kessler, F. Calcavecchia, T. Kühne, Advanced Theory and Simulations 4
    (2021).
date_created: 2022-10-10T08:15:23Z
date_updated: 2022-10-10T08:15:37Z
department:
- _id: '613'
doi: 10.1002/adts.202000269
intvolume: '         4'
issue: '4'
keyword:
- Multidisciplinary
- Modeling and Simulation
- Numerical Analysis
- Statistics and Probability
language:
- iso: eng
publication: Advanced Theory and Simulations
publication_identifier:
  issn:
  - 2513-0390
  - 2513-0390
publication_status: published
publisher: Wiley
status: public
title: Artificial Neural Networks as Trial Wave Functions for Quantum Monte Carlo
type: journal_article
user_id: '71051'
volume: 4
year: '2021'
...
---
_id: '15725'
abstract:
- lang: eng
  text: Adaptive kinetic Monte Carlo simulation (aKMC) is employed to study the dynamics
    and the diffusion of point defects in the CuInSe2 lattice. The aKMC results show
    that lighter alkali atoms can diffuse into the CuInSe2 grains, whereas the diffusion
    of heavier alkali atoms is limited to the Cu-poor region of the absorber. The
    key difference between the diffusion of lighter and heavier alkali elements is
    the energy barrier of the ion exchange between alkali interstitial atoms and Cu.
    For lighter alkali atoms like Na, the interstitial diffusion and the ion-exchange
    mechanism have comparable energy barriers. Therefore, Na interstitial atoms can
    diffuse into the grains and replace Cu atoms in the CuInSe2 lattice. In contrast
    to Na, the ion-exchange mechanism occurs spontaneously for heavier alkali atoms
    like Rb and the further diffusion of these atoms depends on the availability of
    Cu vacancies. The outdiffusion of alkali substitutional atoms from the grains
    results in the formation of Cu vacancies which in turn increases the hole concentration
    in the absorber. In this respect, Na is more efficient than Rb due to the higher
    concentration of Na substitutional defects in the CuInSe2 grains.
article_number: '1900036'
author:
- first_name: Ramya
  full_name: Kormath Madam Raghupathy, Ramya
  id: '71692'
  last_name: Kormath Madam Raghupathy
  orcid: https://orcid.org/0000-0003-4667-9744
- first_name: Thomas
  full_name: Kühne, Thomas
  id: '49079'
  last_name: Kühne
- first_name: Graeme
  full_name: Henkelman, Graeme
  last_name: Henkelman
- first_name: Hossein
  full_name: Mirhosseini, Hossein
  id: '71051'
  last_name: Mirhosseini
  orcid: 0000-0001-6179-1545
citation:
  ama: Kormath Madam Raghupathy R, Kühne T, Henkelman G, Mirhosseini H. Alkali Atoms
    Diffusion Mechanism in CuInSe            2            Explained by Kinetic Monte
    Carlo Simulations. <i>Advanced Theory and Simulations</i>. Published online 2019.
    doi:<a href="https://doi.org/10.1002/adts.201900036">10.1002/adts.201900036</a>
  apa: Kormath Madam Raghupathy, R., Kühne, T., Henkelman, G., &#38; Mirhosseini,
    H. (2019). Alkali Atoms Diffusion Mechanism in CuInSe            2           
    Explained by Kinetic Monte Carlo Simulations. <i>Advanced Theory and Simulations</i>,
    Article 1900036. <a href="https://doi.org/10.1002/adts.201900036">https://doi.org/10.1002/adts.201900036</a>
  bibtex: '@article{Kormath Madam Raghupathy_Kühne_Henkelman_Mirhosseini_2019, title={Alkali
    Atoms Diffusion Mechanism in CuInSe            2            Explained by Kinetic
    Monte Carlo Simulations}, DOI={<a href="https://doi.org/10.1002/adts.201900036">10.1002/adts.201900036</a>},
    number={1900036}, journal={Advanced Theory and Simulations}, author={Kormath Madam
    Raghupathy, Ramya and Kühne, Thomas and Henkelman, Graeme and Mirhosseini, Hossein},
    year={2019} }'
  chicago: Kormath Madam Raghupathy, Ramya, Thomas Kühne, Graeme Henkelman, and Hossein
    Mirhosseini. “Alkali Atoms Diffusion Mechanism in CuInSe            2         
      Explained by Kinetic Monte Carlo Simulations.” <i>Advanced Theory and Simulations</i>,
    2019. <a href="https://doi.org/10.1002/adts.201900036">https://doi.org/10.1002/adts.201900036</a>.
  ieee: 'R. Kormath Madam Raghupathy, T. Kühne, G. Henkelman, and H. Mirhosseini,
    “Alkali Atoms Diffusion Mechanism in CuInSe            2            Explained
    by Kinetic Monte Carlo Simulations,” <i>Advanced Theory and Simulations</i>, Art.
    no. 1900036, 2019, doi: <a href="https://doi.org/10.1002/adts.201900036">10.1002/adts.201900036</a>.'
  mla: Kormath Madam Raghupathy, Ramya, et al. “Alkali Atoms Diffusion Mechanism in
    CuInSe            2            Explained by Kinetic Monte Carlo Simulations.”
    <i>Advanced Theory and Simulations</i>, 1900036, 2019, doi:<a href="https://doi.org/10.1002/adts.201900036">10.1002/adts.201900036</a>.
  short: R. Kormath Madam Raghupathy, T. Kühne, G. Henkelman, H. Mirhosseini, Advanced
    Theory and Simulations (2019).
date_created: 2020-01-30T13:06:56Z
date_updated: 2022-07-21T09:40:36Z
doi: 10.1002/adts.201900036
language:
- iso: eng
publication: Advanced Theory and Simulations
publication_identifier:
  issn:
  - 2513-0390
  - 2513-0390
publication_status: published
status: public
title: Alkali Atoms Diffusion Mechanism in CuInSe            2            Explained
  by Kinetic Monte Carlo Simulations
type: journal_article
user_id: '71051'
year: '2019'
...