Seung Kyu Min

We present a novel quantum-classical approach to nonadiabatic dynamics, deduced from the coupled electronic and nuclear equations in the framework of the exact factorization of the electron-nuclear wave function. The method is based on the quasiclassical interpretation of the nuclear wave function, whose phase is related to the classical momentum and whose density is represented in terms of classical trajectories. In this approximation, electronic decoherence is naturally induced as an effect of

Trajectory-based mixed quantum-classical approaches to coupled electron-nuclear dynamics suffer from well-studied problems such as the lack of (or incorrect account for) decoherence in the trajectory surface hopping method and the inability of reproducing the spatial splitting of a nuclear wave packet in Ehrenfest-like dynamics. In the context of electronic nonadiabatic processes, these problems can result in wrong predictions for quantum populations and in unphysical outcomes for the nuclear dy

We report the first nonadiabatic molecular dynamics study based on the exact factorization of the electron-nuclear wave function. Our approach (a coupled-trajectory mixed quantum-classical, CT-MQC, scheme) is based on the quantum-classical limit derived from systematic and controlled approximations to the full quantum-mechanical problem formulated in the exact-factorization framework. Its strength is the ability to correctly capture quantum (de)coherence effects in a trajectory-based approach to

Using basis-set extrapolation schemes for a given data set, we evaluated the binding energies and geometries at the complete basis set (CBS) limit at the levels of the second order Møller-Plesset perturbation theory (MP2) and the coupled cluster theory with singles, doubles, and perturbative triples excitations [CCSD(T)]. The systems include the hydrogen bonding (water dimer), aromatic interaction (benzene dimer), pi-H interaction (benzene-water), cation-water, anion-water, pi-cation interaction

We demonstrate that the molecular Berry phase and the corresponding nonanalyticity in the electronic Born-Oppenheimer wave function is, in general, not a true topological feature of the exact solution of the full electron-nuclear Schrödinger equation. For a numerically exactly solvable model we show that a nonanalyticity, and the associated geometric phase, only appear in the limit of infinite nuclear mass, while a perfectly smooth behavior is found for any finite nuclear mass.

Theoretical/computational description of excited state molecular dynamics is nowadays a crucial tool for understanding light-matter interactions in many materials. Here we present an open-source Python-based nonadiabatic molecular dynamics program package, namely PyUNIxMD, to deal with mixed quantum-classical dynamics for correlated electron-nuclear propagation. The PyUNIxMD provides many interfaces for quantum chemical calculation methods with commercial and noncommercial ab initio and semiempi

Mechanical metamaterials exhibit unusual properties, such as negative Poisson's ratio, which are difficult to achieve in conventional materials. Rational design of mechanical metamaterials at the microscale is becoming popular partly because of the advance in three-dimensional printing technologies. However, incorporating movable building blocks inside solids, thereby enabling us to manipulate mechanical movement at the molecular scale, has been a difficult task. Here, we report a metal-organic

In this work, a direct mixed quantum-classical dynamics approach is presented, which combines two new computational methodologies. The nuclear dynamics is solved by the decoherence-induced surface hopping based on the exact factorization (DISH-XF) method, which is derived from the exact factorization of the electronic-nuclear wave function and correctly describes quantum decoherence phenomena. The state-interaction state-averaged spin-restricted ensemble-referenced Kohn-Sham (SI-SA-REKS, or SSR,

Polymeric micelles have been widely used as ideal drug-delivery vehicles with unique advantages. However, fine tuning of the degradation rates of micelles over a wide time frame remains challenging. Herein, we designed and synthesized a novel pH-responsive, hydrophobic epoxide monomer, tetrahydrofuranyl glycidyl ether (TFGE), carrying an acetal group as a cleavable linkage. The hydrolysis kinetics of TFGE was carefully evaluated with representative functional epoxide monomers, such as 1-ethoxyet

Mixed quantum-classical dynamics based on the exact factorization exploits the “derived” electron-nuclear correlation (ENC) term, aiming for the description of quantum coherences. The ENC contains interactions between the phase of electronic states and nuclear quantum momenta, which depend on the spatial shape of the nuclear density. The original surface hopping based on the exact factorization (SHXF) [Ha et al., J. Phys. Chem. Lett. 9, 1097 (2018)] exploits frozen Gaussian functions to construc

Owing to current global environmental concerns, polymers must be prepared under eco-friendly reaction conditions based on sustainable chemistry. In this context, highly efficient photoinduced energy/electron transfer reversible addition–fragmentation chain-transfer (PET-RAFT) polymerization under ambient/aqueous conditions without additives and/or with the aid of sunlight is the optimal approach for producing polymers with well-defined structures. This can be accomplished with a photocatalyst (P

We briefly discuss theoretical studies of the optical properties of self-assembled nanolenses, spintronics of carbon-based materials, and molecular electronics for fast DNA sequencing. We address the super-resolution phenomena of nanolenses, the supermagnetoresistance phenomena of graphene nanoribbon spin valves, and ultrafast DNA sequencing based on the 2-dimensional conductance of a graphene nanoribbon on a nanochannel.

Reactive oxygen species have drawn attention owing to their strong oxidation ability. In particular, the singlet oxygen (¹O₂) produced by energy transfer is the predominant species for controlling oxidation reactions efficiently. However, conventional ¹O₂ generators, which rely on enhanced energy transfer, frequently suffer from poor solubility, low stability, and low biocompatibility. Herein, we introduce a hyperbranched aliphatic polyaminoglycerol (h

Abstract The optimization of the quantum efficiency of single-molecule light-driven rotary motors typically relies on chemical modifications. While, in isolated conditions, computational methods have been frequently used to design more efficient motors, the role played by the solvent environment has not been satisfactorily investigated. In this study, we used multiscale nonadiabatic molecular dynamics simulations of the working cycle of a 2-stroke photon-only molecular rotary motor. The results,