The editorial paints a brief history of the conference – Theoretical Chemistry Symposium, organized by eminent theoretical and computational chemists from India.

Efficiently quantifying kinetic barriers: Estimation of activation energies related to rare catalytic activity transitions of Tyrosine Kinases is challenged by high computational expense and obscurity of optimal system descriptors. Here, an upgraded expectation maximized molecular dynamics formalism is used to estimate transition barriers, which is more efficient than optimal collective-variables derived with experimental insights.

Water dissociation on an oxygen-functionalized h-BN monolayer with and without the graphene layer is investigated using semiempirical calculations. Placing a graphene layer above the h-BN monolayer and continuously tuning the interlayer separation modulates the reaction barrier for the oxygen-induced water dissociation at the bridge site of the h-BN layer, which consequently controls the water-splitting reaction on the free-standing monolayer.

Current status of molecular electrides: Using relevant examples, the required characteristics to qualify as an electride, such as non-nuclear attractor, Laplacian of electron density (∇²(ρ(r)), non-linear optical properties, electron localization function, and non-covalent interactions are analyzed.

Two reactive paths for the collision of Li and HCl are studied using quantum wave packet dynamics. Dynamical resonances are identified as van der Waals type and barrier resonances. They reveal a local-mode behaviour at low energies and survive with the lifetime as long as ∼2.2 ps.

The influence of neighbouring metal dopants (boron and gallium) in altering the catalytic activity of γ-Al₂O₃ is demonstrated using density functional calculations. Gallium greatly improves the catalytic activity of the material. A correlation between H₂ binding energies and the C−H activation free energies is identified.

Molecular dynamics simulations were performed for the translocation of polyelectrolytes (PE) through a nanopore, which elucidated a synergistic coupling between the salt-concentration-induced screening effect and the drift force originating from the salt-concentration gradient, thus affecting the translocation time.

The protein dipole moment serves as a reaction coordinate to follow irreversible protein unfolding and reversible structural polarization in simulations under strong and weak electric fields respectively.

Ab initio adiabatic and quasi-diabatic potential energy surfaces are constructed for the charge transfer reaction of He⁺ with N₂. The non-adiabatic interactions among the potential energy curves drive the charge transfer reaction and corroborate the experimental findings.

The acy-BP nanosheets are structurally stable and coupled with anisotropic mechanical properties and Dirac electronic properties. They are potential candidates for Li-ion battery anodes with optimal binding energies, diffusion barriers and open circuit voltage.

Vibronic coupling in the first four electronic states of symmetric linear Cyanogen radical cation is studied. Effect of Renner-Teller coupling of electronic states on the vibronic band structure, nonradiative decay and and radiative emission of these four electronic states are examined at length. The electronic potential energy surfaces and their coupling surfaces calculated with the aid of ab initio quantum chemistry methods and first principles nuclear dynamics calculations are carried out on the coupled manifold of electronic states.

The classical dynamics study of the E−Z isomerization reaction of guanidine shows that 15 % of the trajectories follow the second-order saddle pathway. The dynamics was found to be highly non-statistical. Following the dynamics in the frequency ratio spaces reveal the existence of resonance junctions and long-lived quasi-periodic trajectories in the phase space associated with non-RRKM behavior.

A Synergistic inter-relationship among various cluster amplitudes during Coupled Cluster optimization procedure has been analytically established based on an implicit temporal hierarchy. With significant reduction in the number of independent parameters and memory requirement, the methodology is shown to be nearly as accurate as canonical coupled cluster.

Noise stabilized molecular dynamics together with screened localized orbitals allow achieving a significant speed up in molecular dynamics (MD) simulations. The authors demonstrate the application of this approach in studying the redox properties of the aqueous Fe²⁺/Fe³⁺ system by carrying out long MD simulations.

Resonance state forms due to scattering of an electron off a neutral target. This state is buried in the continuum and revealed by the application of multiconfigurational propagator method augmented by a complex absorbing potential.

Electronic substitution effects on the excited state properties of indole and its derivatives – tryptophan, serotonin and melatonin are studied using time dependent density functional calculations. The contribution of the small in-plane adjacent groups increases the electron density of the indole ring whereas the out-of-plane long substituent groups have minor effects.

Coflin-1 membrane interaction: Coarse-grain simulations are used to investigate the binding of cofilin-1 to phosphoinositide-lipid-containing membranes. The authors show that PIP₂ and PIP₃ lipids are the main lipids that interact closely with cofilin-1. Both the charge and geometry of the head-group of the PIP₂ lipid play important roles in these interactions.

Origin of the large hydrogen uptake capacity of Mn(II)-based [(Mn₄Cl)₃(BTT)₈]³⁻(BTT³⁻=1,3,5-benzenetristetrazolate) metal-organic framework is studied using periodic density functional theory calculations. The calculations show that there are many strong binding pockets available for hydrogen to bind, thus enhancing the uptake capacity.

Throwing light on the characteristic interactions at play when anions adsorb onto graphynes.

The two-leg ladder model with ferro- and antiferromagnetic exchange interactions along the legs and coupling with ferro- or antiferromagnetic rung interactions is considered here. A DMRG analysis of this model reveals an intriguing phase diagram with five distinct phases. The NCF phase is the most dominant phase, followed by FM, AFM, dimer and m-1/4 phase.

Propellane consists of three wings separated by a saturated common C−C linkage. This makes it an ideal system to design a molecule that can absorb in three different wavelength regions, each corresp-onding to one of the wings. Additionally, if the wings are chosen to be nonlinear optically active then it can pave a path to design an interesting nonlinear optically active material.

The electrocyclization of gauche-1,3-Butadiene (GBUT) to Bicyclobutane (BIBUT) and its substituted −F and −CH₃ derivatives were studied. The GBUT/F-GBUT to BIBUT/F-BIBUT photoconversion can occur via a conical intersection (CI) geometry, whereas the CH₃-GBUT to CH₃-BIBUT conversion proceeds via a thermal pathway with a characterized transition state (TS). For all the three systems “on the fly” surface hopping molecular dynamics were performed.

A minimalistic mathematical model can reconcile a wide variety of experimental features of p53 in a context-specific manner. It can also predict ways to sensitize the resistant and sensitive cells towards apoptosis upon DNA damage.

The activity of reduced molybdenum oxides was studied by DFT+U calculations. The calculations reveal that molybdenum dioxide is highly active for hydrodeoxygenation reactions, however, it may get poisoned by strongly adsorbing reactants (anisole).

Semiclassical trajectory calculations for the nonadiabatic quenching of OH(A) by H₂ on a modified ab initio diabatic potential energy matrix report branching fraction of the adiabatic and nonadiabatic channels and the product internal state distribution in the nonadiabatic quenching channel. The results are in reasonable agreement with experimental and previous quantum calculations.

A molecular-level interpretation of the solvation environment associated dynamics and spectroscopic properties of the nitrile stretching mode of the thiocyanate probe in protic ionic liquid, ethylammonium nitrate (EAN) versus water (H₂O) from a fast and accurate computational method is reported. The frequency dependence of the reorientation anisotropy dynamics of SCN⁻ within the ionic liquid framework indicates multiple hydrogen-bonding subensembles in EAN as compared to H₂O.

Binding modes of Glycosaminoglycans (GAGs) with chemokine IL8 were identified. IL8-GAGs bind through favorable electrostatic and non-polar solvation interactions. Multiple minima separated by energy barriers are mainly observed for the bond formation of almost all the GAGs compared to the free states. Both direct and water-mediated IL8-GAG hydrogen-bonded networks suggest that apart from the cationic surface, the interactions could happen through other nonspecific surfaces of IL8.

Beyond Born-Oppenheimer approach is employed to construct diabatic potential energy surfaces of four excited electronic states of pyrazine. Time-Dependent Discrete Variable Representation dynamics is subsequently performed over those surfaces to compute its photoabsorption spectra. Those spectral envelops show better agreement with the experimental ones compared to other theoretical results.

The molecular tailoring approach reveals the energetics of self- and cross-associating hydrogen bonds and cooperativity in ammonia-water clusters.

Binary mixtures of active-passive particles in convection arrays exhibit a conspicuous phase separation into two distinct colloidal fluids for strong self-propulsion of the active fraction. The passive fluid circulating inside the convection rolls and the active one accumulating in stagnation areas along the array walls. On the other hand, a little fraction of weak active particles exert a strong stirring action on a passive colloidal fluid.

For encapsulated small molecules (H₂, HF, H₂O, NH₃ and CH₄), the energy decomposition analysis reveals that the dispersion and electrostatic energy components are the major sources of stabilization, with the latter being dominant in most cases.

All-atom molecular dynamics simulations are carried out on amyloid-β (13-42) peptides implementing Hamiltonian replica exchange method with solute tempering. The results reveal conformations that remain inaccessible using experimental techniques. Investigations revealed key interactions that could trigger seed formation required for disease relevant species generation.

The energy transfer within molecular wires is explored from classical, quantum, and quasi-classical approaches to understand the origin of population oscillations and quantum coherence.

Successive addition of monomers leads to a consequent rise in the association energy, although to a much greater extent in PDI and t-PDI than in perylene, while the steric interactions in t-PDI quench the cooperativity in its SMP formation. A detailed analysis reveals the presence of π-π, π-hole⋅⋅⋅O=C, and π-hole⋅⋅⋅S=C electrostatic interactions playing crucial role in the self-assembly process.

The effect of protonation and deprotonation on the ionization potential, double ionization potential, and lifetime (or decay width) of the temporary bound state in non-radiative decay processes is studied.

Denaturation inhibiting agent choline chloride forces solvent (water) towards methane, which gets reflected in the spatial distribution of water. This arrangement of solvent and the co-solvent results in two populated orientations - tangential and bulk, and affects the tetrahedral hydrogen bonding network of water.

Density functional theory reveals that Mn_0.5Co_0.5PS₃(100) is a potential next-generation platinum-free oxygen reduction reaction electrocatalyst for fuel cell applications.

Atomistic molecular dynamics simulations are used to investigate the effect of alkali and alkaline metal ions on the trans conformation of the intrinsically disordered region of the cellular prion protein. The Li⁺ ions at lower concentration is found to efficiently shift the dynamic equilibrium of the disordered protein segment from toxic beta-hairpin state to natural alpha-helical conformation. This ion specific effect is further compromised at higher salt concentration and lower charge density.

Holey carbon nitride monolayers as potential anode materials of LIBs.

The molecular tailoring-based approach reveals the correct energetic ordering in various types of hydrogen bond strengths in methanol-water clusters.

A collective outlook on the most recent advancement in understanding the microstructure and dynamics associated with hydrophobic deep eutectic solvents (HDESs) is presented. An overview on how the integration of experiments and computational techniques can help understand the mechanism of extraction using HDESs is also provided.

The origin of resonant character in the low energy electron impact two-body neutral fragmentation of methane yielding CH3 radical and a hydrogen atom is reported. This molecular fragmentation by the resonant capture, yielding only neutral fragments, are a manifestation of the autodetachment phenomena during the course of fragmentation reaction.

Nature of Tetrel Bond: Quantum mechanical is carried out to investigate the strength and nature of the N…Si tetrel bond between H₂SiO and substituted pyridines. The strength and nature of the π-hole based N^…Si bond is compared with the N^…C tetrel bond and N^…S chalcogen bond. The effect of substituent on the binding energy is explored. Hyperconjugation interaction between the two units plays significant role in stabilizing the complex. The N…Si tetrel bond is similar to the coordinate covalent bond.

A complementary perspective to stationary-state Schrödinger-Pauli/Schrödinger theory of electrons in an electromagnetic field is described. The perspective is that of the individual electron via its equation of motion or ‘Quantal Newtonian’ First Law. The perspective is elucidated by application to semiconductor quantum dots in a magnetic field in a ground, and first excited singlet and triplet states. The relationship of the new perspective to Quantal and traditional density functional theories is briefly explained.

Employing a fragment-based molecular tailoring approach, the construction of PES of dipeptides using correlated methods with the computational economy is demonstrated. The MP2/aug-cc-pVTZ and CCSD/aug-cc-pVDZ level PES are constructed for prototype dipeptides viz. alanine-alanine and alanine-proline.

The underlying dynamics of binding and unbinding of a ligand to an enzyme and its interactions with amino acid residues modify the enthalpy, entropy, and total binding free energy estimated using a single molecular dynamics trajectory in combination with the molecular mechanics with generalised Born and surface area solvation (MM/GBSA) method.

Different temporal behaviors related to spreading the inhomogeneous control parameter over the spatial domain are illustrated. Traveling wave direction change occurs only with slight asymmetry in the control parameter profile.

Multiple Transcription Factors (TFs) search on Nucleosome: The target search efficiency for a pair of TFs on nucleosome DNA relies on nucleosome dynamics, protein-protein complex formation rates, their dissociation kinetics and spatial position of their cognate motifs. Using a discrete-state stochastic theoretical model and Monte Carlo simulation, we elucidate the molecular details of their target search processes.

An inexpensive computational method is developed to unravel the structure-property relationship of complex covalent organic framework (COFs) molecules toward CO₂ capture. The model is tested on boronic acid derived COFs. Increasing the number of −NH₂ attached to aromatic moiety makes COFs better candidates for CO₂ capture at room temperature and an increase in the size of the aromatic ring facilitates CO₂ capture at high pressure.

Vibrational sum frequency generation spectra of water are calculated for air-water interfaces covered by alcohol molecules for different surface coverages. Two different alcohols of varying hydrophobic parts are considered and the spectral features are connected to the interfacial structure and interactions. The effects of coupling between vibrational modes of interest are also presented.

Complete destruction of tunnelling (CDT) can only be achieved with continuous temporal perturbation on symmetric double and triple well model quantum systems. The discontinuous one shows tunnelling without CDT or over-barrier transition, depending on the nature of reversal time, whether fixed or random, and the spatial symmetry of applied perturbation.