Research interests

Our research is inspired by the current needs of applied research on two-dimensional (2D) materials for flexible and ultrathin functional devices. We study physical properties of 2D materials like electronic and optical properties including excitonic effects and their sensitivity vs. defects and environment. For the presence of delicate interplay of multiple effects in 2D materials, accurate predictions of their properties require accurate and costly many-body methods instead of usual density functional theory

• Ketolainen T., Macháčová N., Karlický F.: Optical Gaps and Excitonic Properties of 2D Materials by Hybrid TD-DFT: Evidences for Monolayers and Prospects for vdW Heterostructures. (with Cover Art) J. Chem. Theory Comput. 16, 9, 5876–5883, 2020 (ACS)

• Kolos M., Karlický F.: Accurate Many-Body Calculation of Electronic and Optical Band Gap of Bulk Hexagonal Boron Nitride. Phys. Chem. Chem. Phys. 21 (7), 3999-4005, 2019 (RSC)

• Karlický F., Turoň J.: Fluorographane C2FH: stable and wide band gap insulator with huge excitonic effect.Carbon 135, 134-144, 2018 (Elsevier)
• Karlický F., Otyepka M.: Band Gaps and Optical Spectra from Single- and Double-Layer Fluorographene to Graphite Fluoride: Many-Body Effects and Excitonic States. Ann. Phys. 526(9-10), 408-414, 2014 (Wiley)

Fixed-node diffusion Monte Carlo (FNDMC) is a many-body electronic structure approach promising for its accuracy, massive parallelism, low-order polynomial CPU cost scaling, and, direct treatment of extended systems. For computational reasons, FNDMC is most often used with single-determinant trial wave functions. We are trying to understand the limits of this approach in area of noncovalent interactions.

• Ditte M., Dubecký M.: Fractional charge by fixed-node diffusion Monte Carlo simulation. Phys. Rev. Lett. 123 (15), 156402, 2019 (APS)

• Dubecký M., Jurečka P., Mitas L., Ditte R., Fanta R.: Toward Accurate Hydrogen Bonds by Scalable Quantum Monte Carlo. J. Chem. Theory Comput. 15 (6), 3552-3557, 2019 (ACS)
• Dubecký M.: Bias cancellation in one-determinant fixed-node diffusion Monte Carlo: Insights from fermionic occupation numbers. Phys. Rev. E 95, 033308, 2017 (APS)
• Dubecký M., Mitas L., Jurečka P.: Noncovalent Interactions by Quantum Monte Carlo. Chem. Rev. 116, 5188-5215, 2016 (ACS)

We often support our colleagues from experiment by calculations. We study interfaces between nanostructures or materials surfaces by density functional theory. We typically predict band gaps, optical absorptions, work functions, charge redistribution or evaluate stability, doping etc.

• Han H., Karlický F., Pitchaimuthu S., Shin S. H. R., Chen A. P., Highly Ordered N‐Doped Carbon Dots Photosensitizer on Metal–Organic Framework‐Decorated ZnO Nanotubes for Improved Photoelectrochemical Water Splitting. Small 15 (40), 1902771, 2019 (Wiley)

• Dubecký F., Zaťko B., Kolesár V., Kindl D., Hubík P., Gombia E., Dubecký M.: Charge collection efficiency of Pt vs. Mg contacts on semi-insulating GaAs. Appl. Surf. Sci. 467-468, 1219-1225, 2019 (Elsevier)
• Han H., Kment Š., Karlický F., Wang L., Naldoni A., Schmuki A., Zbořil R.: Sb-doped SnO2 Nanorods Underlayer Effect to the alpha-Fe2O3 Nanorods Sheathed with TiO2 for Enhanced Photoelectrochemical Water Splitting. Small 14(9), 1703860, 2018 (Wiley)
• Han H., Riboni F., Karlický F., Kment Š., Goswami A., Sudhagar P., Yoo J., Wang L., Tomanec O., Petr M., Haderka O., Terashima C., Fujishima A., Schmuki A., Zbořil R.: alpha-Fe2O3/TiO2 3D Hierarchical Nanostructures for enhanced Photoelectrochemical Water Splitting. Nanoscale 9, 134-142, 2017 (RSC)

We are interested in properties of light atomic clusters which are strongly quantum and nuclear delocalization effects must be included. Quantum motion of nuclei is described by quantum Monte Carlo methods. Further, we focus on transition metal clusters and nanoparticles, inspired by their important practical applications, ranging from the steel industry to water remediation technologies. Namely, the theoretical description of nanoscale zero-valent iron (nZVI) and its reactivity is still challenging.

• Kolos M., Tunega D., Karlický F.: Theoretical study of adsorption on iron sulfides towards nanoparticles modeling. Phys. Chem. Chem. Phys. 22, 23258-23267, 2020 (RSC)

• Ćosić R., Karlický F., Kalus R.: Photoabsorption spectra of small HeN+ clusters (N = 3, 4, 10). A quantum Monte Carlo modeling. Chem. Phys. Lett. 700, 96-101, 2018 (Elsevier)
• Karlický F., Otyepka M.: Challenges in the Theoretical Description of Nanoparticle Reactivity: Nano Zero-Valent Iron. (withCover Art) Int. J. Quantum Chem. 114(15), 987-992, 2014 (Wiley)
• Kalus R., Karlický F., Lepetit B., Paidarová I., Gadéa F.X.: Photoabsorption spectrum of helium trimer cation – theoretical modeling. J. Chem. Phys. 139(20), 204310, 2013 (Am. Inst. Phys.)