Alexey V. Akimov

PhD

Alexey Akimov.

Alexey V. Akimov

PhD

Alexey V. Akimov

PhD

Research Interests

Theoretical and computational chemistry; Quantum and classical molecular dynamics, nonadiabatic dynamics, computations in large-scale systems, semiempirical methods; electron-nuclear coupling, simulation of spin, charge, and excitation energy transfer; Solar energy conversion materials, nanomaterials and nanoscale systems.

Education

  • PhD, Rice University, Houston, Texas, USA, 2011
  • MA, Rice University, Houston, Texas, USA, 2009
  • MS, M.V. Lomonosov Moscow State University, Moscow, Russia, 2007

Awards and Honors

  • Stephen C. Hofmann Fellowship, Rice University, 2010

Specializations

Theory and computations in quantum dynamics: nonadiabatic molecular dynamics, non-local quantum effects and quantum entanglement, large-scale computations. Theory and simulation of charge, spin, and excitation energy transfer in solar energy conversion materials; electron-vibronic coupling in functional nanomaterials.

Research Summary

Our research revolves around the following main directions:

  1. Quantum dynamics. We are interested in fundamental theory and methodology of quantum dynamics. Both are needed for accurate and efficient quantum dynamics simulations. Our present focus is on the trajectory-based descriptions of nonadiabatic processes (e.g. charge transfer or excitation energy relaxation). Within this framework, we look to understand the sources of inaccuracies in approximate quantum dynamics techniques and eventually fix them. In particular, the topics being addressed are: the representation invariance (dependence on basis set), the non-local quantum effects (e.g. tunneling, uncertainty principle, decoherence), as well as the quantum entanglement (trajectory cross-talk in the ensemble description).
  2. Largescale computations. We are interested in simulating quantum dynamical processes in large atomistic systems. To address the scale limitations, we develop efficient computational strategies and new theoretical approaches. The main foci are on the semiempirical and model Hamiltonians as well as on the fragmentation-based linear-scaling methods for electronic structure computations. We implement and maintain our own codes for performing quantum dynamics simulations in atomistic and model systems.
  3. Solar energy conversion materials and functional nanomaterials. The theories and computational tools we develop are ultimately used to gain mechanistic insights into operation of solar energy conversion (photovoltaics, photocatalytics) materials as well as functional nanomaterials (e.g. light-driven nanomachines). We investigate dynamics of charge and spin transfer, excitation energy relaxation, and light-induced nuclear dynamics (e.g. photochemical transformations). The systems we study include condensed crystalline or soft (bio) matter, nanoscale clusters (quantum dots) and molecular complexes, as well as interfaces and exotic 1D (nanotubes) and 2D structures.

Selected Recent Publications

  • [Invited paper for a special issue: "Emerging Leaders"] Pradhan, E.; Sato, K.; Akimov, A. V. "Non-Adiabatic Molecular Dynamics with delta-SCF Excited States" J. Phys.: Condens. Matter. 2018 30, 484002 link  [technical details]
  • Akimov, A. V. "A Simple Phase Correction Makes a Big Difference in Nonadiabatic Molecular Dynamics" J. Phys. Chem. Lett. 2018  9, 6096-6102 link [technical details]
  • Sato, K.; Pradhan, E.; Asahi, R.; Akimov, A. V. "Charge transfer dynamics at the boron subphthalocyanine chloride/C60 interface: non-adiabatic dynamics study with Libra-X" Phys. Chem. Chem. Phys. 2018  20, 25275-25294 link  [technical details]
  • Li, W.; Zhou, L.; Prezhdo, O. V.; Akimov, A. V. "Spin-Orbit Interactions Greatly Accelerate Nonradiative Dynamics in Lead Halide Perovskites" ACS Energy Lett. 2018  3, 2159-2166 link  [technical details]
  • Smith, B. A.; Akimov, A. V. "Entangled trajectories Hamiltonian dynamics for treating quantum nuclear effects" J. Chem. Phys. 2018  148, 144106 link [technical details]
  • Akimov, A. V.; "Stochastic and Quasi-Stochastic Hamiltonians for Long-Time Nonadiabatic Molecular Dynamics" J. Phys. Chem. Lett.  2017  8, 5190-5195 link
  • Nijamudheen, A.; Akimov, A. V.; "Excited-State Dynamics in Two-Dimensional Heterostructures: SiR/TiO2 and GeR/TiO2 (R = H, Me) as Promising Photocatalysts" J. Phys. Chem. C  2017  121, 6520-6532 link
  • Akimov, A. V.; "Nonadiabatic Molecular Dynamics with Tight-Binding Fragment Molecular Orbitals" J. Chem. Theory Comput.  2016  12, 5719-5736 link
  • Lin, Y.; Akimov, A. V. "Dependence of Nonadiabatic Couplings with Kohn–Sham Orbitals on the Choice of Density Functional: Pure vs Hybrid" J. Phys. Chem. A.  2016  120, 9028-9041 link
  • Akimov, A. V.; "Libra: An open-Source “methodology discovery” library for quantum and classical dynamics simulations" J. Comput. Chem.  2016  37, 1626-1649 link