Computer Simulations

In order to get a better understanding of atomic-level dynamics, kinetics and thermodynamics in solids under particle irradiation and/or thermal and mechanical load,  atomistic simulations are performed. The main focus is on investigations of iron-based alloys and semiconductor materials.

Research subjects:

• Thermodynamics and kinetics of defects; Irradiation-induced defect formation
• Formation and properties of nanoclusters embedded in solids
• Ion-beam mixing of Si- and Ge-multilayers
• Epitaxial recrystallization of amorphous Si and Ge layers

Methods:

• First-Principle Simulations
• Molecular Dynamics
• Monte-Carlo Simulations
• Binary Collision Simulations

Publications since 2020:

G. Tejaswini, Anjana E Sudheer, Amrendra Kumar, M. Vallinayagam, Pavan Kumar Perepu, Attila Cangi, Mani Lokamani, M. Posselt, M. Zschornak, C. Kamal, D. Amaranatha Reddy, D. Murali: Prediction of atomic H adsorption energies in metalloid doped MSSe (M = Mo/W) Janus layers: A combined DFT and machine learning study, https://arxiv.org/pdf/2511.16263

A.E. Sudheer, M Vallinayagam, G Tejaswini, Amrendra Kumar, M Posselt, C Kamal, M Zschornak, D Murali: Thermoelectric properties of Lead halide Janus layers - A theoretical investigation, https://arxiv.org/pdf/2509.16992

M. Vallinayagam, A. E. Sudheer, A. Kumar, G. Tejaswini, M. Posselt, C.Kamal, D. Murali, M. Zschornak: Thermoelectric properties of SbXY (X = Se, Te; Y = Br, I) Janus layers, https://arxiv.org/pdf/2512.12626

Anjana E Sudheer, G. Tejaswini, M. Posselt, D. Murali: Design of novel SnIX (X=Br/Cl) Janus layers: Electronic, optical, photocatalytic properties, as well as defect and strain engineering, J. Mater. Chem. A (2025), online first August 26, 2025, DOI: 10.1039/D5TA04079E finally: J. Mater. Chem. A 13 (2025) 34873

G. Tejaswini, Anjana E Sudheer, Amrendra Kumar, Pavan Kumar Perepu, M. Vallinayagam, C. Kamal, S. Mani Prakash, M.Posselt, M. Zschornak, D. Murali: Hydrogen adsorption energy trends in Mo/WXY (X, Y = S, Se, Te) regular and Janus TMD monolayers: A first-principles and machine learning study, J. Mater. Chem. A (2025), online first May 8, 2025, DOI: 10.1039/D5TA02028J finally: J. Mater. Chem. A 13 (2025) 19896-19910

C. Karthikeyan, G. Tejaswini, Anjana E. Sudheer, M. Vallinayagam, M. Posselt, M. Zschornak, D. Murali: Theoretical insights into PtSSe–SnSSe heterostructures for renewable energy applications, J. Mater. Chem. C (2025), online first May 3, 2025, DOI: 10.1039/d5tc00301f finally: J. Mater. Chem. C 13 (2025) 11904-11916

A. E. Sudheer, D. Murali, M. Posselt: Accurate determination of excitonic spectra of monolayer Selenium - PtS2 van der Waals heterostructure, Advances in Photonics Integrated Circuits, LASER and Applications, Proceedings of PHOTONICS 2023, Lecture Notes in Electrical Engineering Volume 1241 (2024): Springer, ISBN 978-981-97-6163-0, pp. 105-11, DOI: 10.1007/978-981-97-6164-7

A. E. Sudheer, A. Kumar, G. Tejaswini, M. Vallinayagam, M. Posselt, M. Zschornak, C. Kamal, D. Murali: First principles study on stability, electronic and optical properties of 2D SbXY(X=Se/Te, Y=I/Br)Janus layers, Online First November 2024 as Phys. Chem. Chem. Phys. DOI: 10.1039/D4CP04077E finally: Phys. Chem. Chem. Phys. 26 (2024) 29371-29383

G. Tejaswini, A. E Sudheer, M. Vallinayagam, M. Posselt, M. Zschornak, S. Maniprakasha, D. Murali: Band alignment in CdS-α-Te van der Waals heterostructures for photocatalytic applications: Influence of biaxial strain and electric field, Online First November 2024 as Phys. Chem. Chem. Phys. DOI: 10.1039/D4CP03368J finally: Phys. Chem. Chem. Phys. 26 (2024) 29339-29350

A. M. Jakob, S. G. Robson, H. R. Firgau, V. Mourik, V. Schmitt, D. Holmes, M. Posselt, E. L.H. Mayes, D. Spemann, J. C. McCallum, A. Morello, D. N. Jamieson: Scalable atomic arrays for spin-based quantum computers in silicon, Online First: August 2024 as Adv. Mater. 2024, 2405006, in a regular volume: Adv. Mater. 36 (2024) 2405006

T. Böckendorf, J. Kirschbaum, F. Kipke, D. Bougeard, J. Lundsgaard Hansen, A. Nylandsted Larsen, M. Posselt, H. Bracht: Experimental and theoretical studies on self-diffusion in amorphous germanium, AIP Adv. 14 (2024) 065129

M. Vallinayagam, J. Karthikeyan, M. Posselt, D. Murali. M. Zschornak: Metalloid-doping in SMoSe Janus layers: first principles study on efficient catalysts for the hydrogen evolution reaction, J. Mater. Chem. A, online first 16.2.2024 (10.1039/d3ta07243f) in a regular volume: J. Mater. Chem. A 12 (2024) 7742

A. E. Sudheer, G. Tejaswini, D. Murali, M. Posselt: First Principles Investigation on Structural and Optoelectronic Properties of newly designed Janus Lead Halides PbXY (X, Y = F, Cl, Br, I ),  http://arxiv.org/abs/2312.04122 (2023), Comput. Mater. Sci. 243 (2024) 113123

A. M. Jakob, S. G. Robson, H. R. Firgau, V.  Mourik, V. Schmitt, D. Holmes, M. Posselt, E. L. H. Mayes, D. Speemann, A. Morello, D. N. Jamieson: Scalable Atomic Arrays for Spin-Based Quantum Computers in Silicon, http://arxiv.org/abs/2309.09626 (2023)

D. Radić, M. Peterlechner, K. Spangenberg, M. Posselt, H. Bracht: Challenges of Electron Correlation Microscopy on Amorphous Silicon and Amorphous Germanium, Microsc. Microanal. 29 (2023) 1579

Sruthil Lal S.B, Lokamani, Kushal Ramakrishna, Attila Cangi, D. Murali, Matthias Posselt, Assa Aravindh Sasikala Devi, Alok Sharan: Ab initio insights on the ultrafast strong-field dynamics of anatase TiO2, http://arxiv.org/abs/2306.17554 (2023), Phys. Rev. B 108 (2023) 195149

M. Vallinayagam, A. E. Sudheer, A. S. Aravindh, D. Murali, N. Raja, R. Katta, M. Posselt, M. Zschornak: Novel metalless chalcogen-based Janus layers: A Density Functional Theory study, The Journal of Physical Chemistry C 127 (2023) 17029

N. Raja, D. Murali, S.V.M. Satyanarayana, M. Posselt: Y doping of BaZrO₃ may lead to optimum conditions for proton conduction at operating temperature of solid oxide fuel cells: a first principles study, Mater. Res. Express 10 (2023) 065504

D. Radić, M. Peterlechner, M. Posselt, H. Bracht: Fluctuation Electron Microscopy on Amorphous Silicon and Amorphous Germanium, Microsc. Microanal. 29 (2023) 477

D. Radić, M. Peterlechner, M. Posselt, H. Bracht: The Impact of Energy Filtering on Fluctuation Electron Microscopy, Microsc. Microanal. 29 (2023) 189

M. Posselt, H. Bracht, Mahdi Ghorbani-Asl, D. Radić: Atomic mechanisms of self-diffusion in amorphous silicon, http://arxiv.org/abs/2208.07025 (2022), AIP Advances 12 (2022) 115325

D. Radić, M. Peterlechner, M. Posselt, H. Bracht: Treating Knock-On Displacements in Fluctuation Electron Microscopy Experiments, Microsc. Microanal. 28 (2022) 2036

M. Posselt, H. Bracht, D. Radić: Atomistic simulations on the relationship between solid-phase epitaxial recrystallization and self-diffusion in amorphous silicon, J. Appl. Phys. 131 (2022) 035102

S. B. Sruthil Lal, A. Sharan, M. Devaraj, M. Posselt, A. A. Sasikala Devi: Quasiparticle electronic structure and optical response (G0W0+BSE) of anatase TiO2 starting from modified HSE06 functionals, http://arxiv.org/abs/2112.03027 (2021), Modified HSE06 functional applied to anatase TiO2 : influence of exchange fraction on the quasiparticle electronic structure and optical response, Electron. Struct. 4 (2022) 045001

A. M. Jakob, S. G. Robson, V. Schmitt, V. Mourik, M. Posselt, D. Spemann, B. C. Johnson, H. R. Firgau, E. Mayes, J. C. McCallum, A. Morello, D. N. Jamieson: Deterministic Shallow Dopant implantation in silicon with detection confidence upper-bound to 99.85% by ion–solid interactions, Online First: October 2021 as Adv. Mater. 2021, 2103235, in a regular volume: Adv. Mater. 34 (2022) 2103235

M. Posselt (Editor): Special Issue "First-Principle and Atomistic Modelling in Materials Science", Materials (2019-2021, 10 articles, 1 Letter. finished on March 17, 2021) Editorial:  Materials 14 (2021) 1469, whole issue: https://www.mdpi.com/journal/materials/special_issues/Princ_Model

M. Vallinayagam, M. Posselt, S. Chandra: Electronic structure and thermoelectric properties of Mo-based dichalcogenide monolayers locally and randomly modified by substitutional atoms, RSC Adv. 10 (2020) 43035

A. T. AlMotasem, M. Posselt, T. Polcar: Deformation behavior of nanocrystalline body-centered cubic iron with segregated, foreign interstitial: A molecular dynamics study, Materials 13 (2020) 5351

S. B. Sruthil Lal, D. Murali, M. Posselt, A. Sharan: Accurate determination of quasi-particle electronic and optical spectra of anatase titanium dioxide, AIP Conf. Proc. 2265 (2020) 030375

S. Prucnal, M. O. Liedke, X. Wang, M. Butterling, M. Posselt, J. Knoch, H. Windgassen, E. Hirschmann, Y. Berencen, L. Rebohle, M. Wang, E. Napoltani, J. Frigerio, A. Ballabio, G. Isella, R. Hübner, A. Wagner, H. Bracht, M. Helm, S. Zhou: Dissolution of donor-vacancy clusters in heavily doped n-type germanium, New J. Phys. 22 (2020) 123036

D. Radić, S. Hilke, M. Peterlechner, M. Posselt, G. Wilde, H. Bracht:  Comparison of experimental STEM conditions for fluctuation electron microscopy, Microsc. Microanal. 26 (2020) 1100

X. Wang, J. Faßbender, M. Posselt: Mutual dependence of oxygen and vacancy diffusion in bcc Fe and dilute iron alloys, Phys. Rev. B 101 (2020) 174107