About

Evgeni Penev is an Associate Research Professor at Rice University. He studied physics at the St. Clement of Ohrid University of Sofia in Bulgaria, where he received his M.S. degree in solid-state physics. He earned his PhD in Computational Materials Science from the Fritz Haber Institute of the Max Planck Society in Germany, and was awarded the Otto Hahn Medal for Outstanding Scientific Achievement. His research focuses on the computational materials science of carbon-based systems and novel low-dimensional materials. His interests and experience also include semiconductor nanostructures, conventional and high-temperature superconductivity, biological systems, as well as methods and tools development.

Research topics

• Materials science
• Computer Science
• Nanotechnology
• Composite material
• Inorganic chemistry
• Psychology
• Chemical physics
• Mathematics
• Physics
• Computational chemistry
• Management science
• Engineering
• Physical chemistry
• Chemical engineering
• Metallurgy
• Mechanics
• Geometry
• Algorithm
• Organic chemistry
• Biochemical engineering
• Chemistry

Selected publications

• Possibilities and Limits of DNA-Enabled Programmable 2D Self-Assembly

  ACS Applied Materials & Interfaces · 2025-05-05

  article

  Programmable self-assembly provides a promising avenue to improve upon traditional synthesis and create multicomponent materials with emergent properties and arbitrary nanoscale complexity. However, its most successful realizations utilizing DNA often use complicated arduous procedures that result in low yields. Here, we employ coarse-grained molecular dynamics to uncover the ranges of temperatures and misbinding strengths needed for successful one-pot self-assembly of generic, two-dimensional (2D), and distinguishable tiles. Analysis of the energies associated with a single-stranded DNA interacting with all other sequences within a mixture revealed that the success of DNA-based assembly is primarily determined by the strongest misbinding a given sequence can encounter with a sequence highly similar to its reverse complement. This enabled us to design optimized sequence ensembles with acceptably weak and consequently rare misbinding. An estimate is provided for the maximum size of, and complexity of sequences needed to synthesize self-assembled structures with high accuracy and yield, with potential relevance for DNA-functionalized low-dimensional materials for electronics and energy storage.

  PublisherDOI

• Ab Initio Molecular Dynamics Insights into Stress Corrosion Cracking and Dissolution of Metal Oxides

  Materials · 2025-01-24 · 3 citations

  articleOpen access

  Oxide phases such as α-Fe2O3 (hematite) and α-Al2O3 (corundum) are highly insoluble in water; however, subcritical crack growth has been observed in humidity nonetheless. Chemically induced bond breaking at the crack tip appears unlikely due to sterically hindered molecular transport. The molecular mechanics of a crack in corundum with a reactive force field reveal minimal lattice trapping, leading to bond breaking before sufficient space opens for water transport. To address this, we model a pre-built blunt crack with space for H2O molecule adsorption at the tip and show that it reduces fracture toughness by lowering the critical J-integral. Then, we explore stress-enhanced dissolution to understand the mechanism of crack tip blunting in the oxide/water system. Density functional theory combined with metadynamics was employed to describe atomic dissolution from flat hematite and corundum surfaces in pure water. Strain accelerates dissolution, stabilizing intermediate states with broken bonds before full atom detachment, while the free energy profile of unstrained surfaces is almost monotonic. The atomistic calculations provided input for a kinetic model, predicting the shape evolution of a blunt crack tip, which displays three distinct regimes: (i) dissolution primarily away from the tip, (ii) enhanced blunting near but not at the apex, and (iii) sharpening near the apex. The transition between regimes occurs at a low strain, highlighting the critical role of water in the subcritical crack growth of oxide scales, with dissolution as the fundamental microscopic mechanism behind this process.

  PublisherOA PDFDOI

• Mechanical Efficiency of Photochromic Nanomotors, From First Principles

  Small · 2024-08-13 · 4 citations

  articleOpen access

  Photochromic molecular motors hold promise for a multitude of potential applications in fields ranging from medicine to communications and structural repair. Yet, it is still a challenge to predict their mechanical efficiency. Here, azobenzene is explored as a representative light-driven nanomotor and estimate its quantum yield of photoisomerization and maximum mechanical efficiency. This is based on first-principles mapping of the 3D potential energy surfaces for the ground and excited states of the trans and cis configurations and identifying the minimum energy pathway for isomerization. A work cycle is devised and identifies force constant as the parameter that resembles temperature in the Carnot heat engine, but with very different efficiencies. The results show that the optomechanical efficiency of azobenzene at constant load is about 5% albeit under ideal conditions. To test the hypothesis, the study also explores the optomechanical efficiency of stilbene and 2-butene and shows that their efficiency does not exceed 5%.

  PublisherOA PDFDOI

• Possibilities and limits of DNA-enabled programmable 2D self-assembly

  ChemRxiv · 2024-05-27 · 1 citations

  preprintOpen access

  Programmable self-assembly provides a promising avenue to improve upon traditional synthesis and create multi-component materials with emergent properties and arbitrary nanoscale complexity. However, its most successful realizations utilizing DNA often use complicated arduous procedures that result in low yields. Here, we employ coarse-grained molecular dynamics to uncover the ranges of temperatures and misbinding strengths needed for successful one-pot self-assembly of generic, two-dimensional (2D), and distinguishable blocks. Analysis of the energies associated with a single-stranded DNA interacting with all other sequences within a mixture revealed that the success of DNA-based assembly is primarily determined by the strongest misbinding a given sequence can encounter with a sequence highly similar to its reverse complement. This enabled us to design optimized sequence ensembles with acceptably weak and consequently rare misbinding. An estimate is provided for the maximum size of, and complexity of sequences needed to synthesize self-assembled structures with high accuracy and yield, with potential relevance for DNA-functionalized low-dimensional materials for electronics and energy storage.

  PublisherOA PDFDOI

• Mechanisms of Defect-Mediated Memristive Behavior in MoS₂ Monolayer

  Nano Letters · 2024-10-03 · 3 citations

  article

  The switching dynamics of a Au∥VS2@MoS2 atomristor is explored by first-principles computations of the atomic-configuration energy and electron transport. It is found that external bias can reduce the energy barrier between the two (high- and low-) conduction states, to achieve nonvolatile resistive switching. We find that the force acting on the switching atom is a combination of electrostatic force (while its charge is induced both electrostatically and chemically) and also by electron-wind, whose effect may hinder the writing process at larger bias. The analysis uncovers how the writing and reading processes of the atomristor depend on several factors: (i) atomic structure details of the Au tip; (ii) the space-gap distance between the tip and MoS2 layer; and (iii) tip metal choice. The fundamental understanding of switching events provides useful guidance for memristor design and possible limitations.

  PublisherDOI

• Limits of Hydrogen-Boosted Superconductivity in Borophene

  The Journal of Physical Chemistry C · 2023-12-29 · 8 citations

  article

  Two-dimensional (2D) boron, borophene, unlike the majority of other 2D materials, features a metallic ground state and is expected to show phonon-mediated superconductivity with a modest critical temperature, Tc. The recent prediction of enhanced Tc through hydrogenation in several 2D materials and the experimentally feasible hydrogenation of borophene naturally provoke the question of whether hydrogen can boost the Tc of borophene. Here, we employ first-principles calculations to examine the electronic structure, phonon dispersion, and electron–phonon coupling of borophene for varying H coverage. While the Tc’s for the selected most stable hydrogenated borophene (“borophane”) polymorphs are found to be not higher but lower than that of the parent borophene, our results suggest that the intrinsic superconductivity of borophene appears robust again modest “disorder” due to hydrogenation.

  PublisherDOI

• Floating Fe Catalyst Formation and Effects of Hydrogen Environment in the Growth of Carbon Nanotubes

  The Journal of Physical Chemistry Letters · 2023-05-01 · 18 citations

  article

  Hydrocarbon conversion to advanced carbon nanomaterials with concurrent hydrogen production holds promise for clean energy technologies. This has been largely enabled by the floating catalyst chemical vapor deposition (FCCVD) growth of carbon nanotubes (CNTs), where commonly catalytic iron nanoparticles are formed from ferrocene decomposition. However, the catalyst formation mechanism and the effect of the chemical environment, especially hydrogen, remain elusive. Here, by employing atomistic simulations, we demonstrate how (i) hydrogen accelerates the ferrocene decomposition and (ii) prevents catalyst encapsulation. A subsequent catalytic dehydrogenation of methane on a liquid Fe nanoparticle showed that carbon dimers tend to be the dominant on-surface species. Such atomistic insights help us better understand the catalyst formation and CNT nucleation in the early stages of the FCCVD growth process and optimize it for potential scaleup.

  PublisherDOI

• Iron corrosion in the “inert” supercritical CO2, ab initio dynamics insights: How impurities matter

  Matter · 2022 · 30 citations

  • Chemical physics
  • Materials science
  • Computational chemistry
  PublisherOA PDFDOI

• Stability and electronic properties of gallenene

  Nanoscale Advances · 2022-01-01 · 11 citations

  articleOpen access

  Two-dimensional metals offer intriguing possibilities to explore the metallic and other related properties in systems with reduced dimensionality. Here, following recent experimental reports of synthesis of two-dimensional metallic gallium (gallenene) on insulating substrates, we conduct a computational search of gallenene structures using the Particle Swarm Optimization algorithm, and identify stable low energy structures. Our calculations of the critical temperature for conventional superconductivity yield values of ∼7 K for gallenene. We also emulate the presence of the substrate by introducing the external confining potential and test its effect on the structures with unstable phonons.

  PublisherOA PDFDOI

• Nucleobase-Bonded Graphene Nanoribbon Junctions: Electron Transport from First Principles

  ACS Nano · 2022-10-05 · 5 citations

  articleSenior author

  Carbon and hydrogen bonding constitute the backbone of life; in the form of graphene, possibly functionalized by DNA nucleobases, these hold promise for the programmable assembly of graphene-based nanoelectronic devices. It is still unknown how hydrogen-bonded junctions inherent in such devices will perform as electron transport media. Here, we design nucleobase-bonded graphene nanoribbons and quantify their quantum transport characteristics using first-principles calculations. Pronounced rectifying behavior and negative differential resistance are found, as well as high conductance of certain structures, with the guanine–cytosine junction in general being superior to the adenine–thymine junction. The identified sensitivity of the conductance to atomic details of the interfaces offers initial hints and guidance for experimental realization. The dependence of current on electrostatic gate doping, with an on/off ratio of ∼102, shows the potential of the junction as a field effect transistor.

  PublisherDOI

Frequent coauthors

• Boris I. Yakobson

  Rice University

  64 shared

• Martin J. Field

  Institut Laue-Langevin

  49 shared

• Stefan Goedecker

  49 shared

• Shantanu Roy

  Indian Institute of Technology Delhi

  49 shared

• Todor M. Mishonov

  Georgi Nadjakov Institute of Solid State Physics

  36 shared

• Zhuhua Zhang

  15 shared

• Peter Kratzer

  University of Duisburg-Essen

  14 shared

• Vasilii I. Artyukhov

  Rice University

  10 shared

Awards & honors

• Otto Hahn Medal for Outstanding Scientific Achievement