Spin–Orbit Couplings for Nonadiabatic Molecular Dynamics at the ΔSCF Level

Mališ, Momir; Vandaele, Eva; Luber, Sandra

doi:10.1021/acs.jctc.1c01046

Cited by 6 publications

(7 citation statements)

References 100 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, the triplet has been found to be a reasonable proxy for modeling CTTS dynamics . Spin–orbit corrections have been introduced for ROKS simulations only very recently, and these effects are neglected here. Experimentally, the spin–orbit coupling splits the CTTS spectrum of I – (aq) into 2 P 3/2 and 2 P 1/2 bands centered at 5.5 and 6.44 eV, respectively .…”

Section: Methodsmentioning

confidence: 99%

Birth of the Hydrated Electron via Charge-Transfer-to-Solvent Excitation of Aqueous Iodide

Carter-Fenk

Johnson

Herbert

et al. 2023

J. Phys. Chem. Lett.

View full text Add to dashboard Cite

A primary means to generate hydrated electrons in laboratory experiments is excitation to the charge-transfer-to-solvent (CTTS) state of a solute such as I–(aq), but this initial step in the genesis of e –(aq) has never been simulated directly using ab initio molecular dynamics. We report the first such simulations, combining ground- and excited-state simulations of I–(aq) with a detailed analysis of fluctuations in the Coulomb potential experienced by the nascent solvated electron. What emerges is a two-step picture of the evolution of e –(aq) starting from the CTTS state: I–(aq) + hν → I–*(aq) → I•(aq) + e –(aq). Notably, the equilibrated ground state of e –(aq) evolves from I–*(aq) without any nonadiabatic transitions, simply as a result of solvent reorganization. The methodology used here should be applicable to other photochemical electron transfer processes in solution, an important class of problems directly relevant to photocatalysis and energy transfer.

show abstract

Section: Methodsmentioning

confidence: 99%

Birth of the Hydrated Electron via Charge-Transfer-to-Solvent Excitation of Aqueous Iodide

Carter-Fenk

Johnson

Herbert

et al. 2023

J. Phys. Chem. Lett.

View full text Add to dashboard Cite

show abstract

“…Although the states are optimized independently and, therefore, not orthogonal, which, in principle, results in a non-Hermitian spin-orbit coupling operator, a recently developed methodology to project the excited state Slater-determinants of corresponding ΔSCF states onto a linear combination of singly excited Slater determinants allows for the calculation of observables where two excited electronic states are involved. 106 The ΔSCF KS determinant (|ψ i ⟩) mapping the electronic density of state i can be expanded as a linear combination of configuration state functions…”

Section: δScf Methodology For Namdmentioning

confidence: 99%

“…3. 106 Analogously, the UV-absorption spectra of the first singlet excited state of a cyclopropanone molecule in vacuum and in aqueous solution were calculated at the ΔSCF level of theory by approximating the transition dipole moment (with electric dipole operator μ) between the ground and S1 states using the CIS expansion of the S1 excited electronic state density,…”

Section: δScf Methodology For Namdmentioning

confidence: 99%

See 1 more Smart Citation

The ΔSCF method for non-adiabatic dynamics of systems in the liquid phase

Vandaele

Mališ

Luber

2022

The Journal of Chemical Physics

View full text Add to dashboard Cite

Computational studies of ultrafast photoinduced processes give valuable insights into the photochemical mechanisms of a broad range of compounds. In order to accurately reproduce, interpret, and predict experimental results, which are typically obtained in a condensed phase, it is indispensable to include the condensed phase environment in the computational model. However, most studies are still performed in vacuum due to the high computational cost of state-of-the-art non-adiabatic molecular dynamics (NAMD) simulations. The quantum mechanical/molecular mechanical (QM/MM) solvation method has been a popular model to perform photodynamics in the liquid phase. Nevertheless, the currently used QM/MM embedding techniques cannot sufficiently capture all solute–solvent interactions. In this Perspective, we will discuss the efficient ΔSCF electronic structure method and its applications with respect to the NAMD of solvated compounds, with a particular focus on explicit quantum mechanical solvation. As more research is required for this method to reach its full potential, some challenges and possible directions for future research are presented as well.

show abstract

“…We will refer to a molecular configuration in which multiple mean-field solutions start to appear as a symmetry-breaking onset (SBO). As the ultimate goal of variational excited state calculations is often the simulation of dynamics in the excited state, − , it is important to ensure that the calculations converge on the solution providing the appropriate value of the energy and atomic forces. While the ground state solution can, by the minimum energy principle, be identified as the one with the lowest energy, an analogous selection principle cannot be used for tracking excited state solutions. , In previous work, we have demonstrated that the mean-field solution for the doubly excited state of ethylene giving the best description of the energy curve along the double bond torsion can be identified based on the conservation of the saddle point order as the wave function undergoes symmetry breaking.…”

Section: Introductionmentioning

confidence: 99%

Calculations of Excited Electronic States by Converging on Saddle Points Using Generalized Mode Following

Levi

Jónsson

2023

J. Chem. Theory Comput.

View full text Add to dashboard Cite

Calculations of excited electronic states are carried out by finding saddle points on the surface describing the variation of the energy of the system as a function of the electronic degrees of freedom. This approach has several advantages over commonly used methods especially in the context of density functional calculations, as collapse to the ground state is avoided, and yet, the orbitals are variationally optimized for the excited state. Such a state-specific optimization makes it possible to describe excitations with large charge transfer, where calculations based on ground state orbitals, such as linear response time-dependent density functional theory, can be problematic. A generalized mode following method is presented where an n th-order saddle point is found by inverting the components of the gradient in the direction of the eigenvectors of the n lowest eigenvalues of the electronic Hessian matrix. This approach has the distinct advantage of following a chosen excited state by its saddle point order through molecular configurations where the symmetry of the single determinant wave function is broken, thereby making it possible to calculate potential energy curves even at avoided crossings, as demonstrated here in calculations of the ethylene and dihydrogen molecules. Results of calculations are, furthermore, presented for charge transfer excitations in nitrobenzene and N-phenylpyrrole, corresponding to fourth- and sixth-order saddle points, respectively, where an approximate initial estimate of the saddle point order could be found by energy minimization with excited electron and hole orbitals frozen. Finally, calculations of a diplatinum–silver complex are presented, illustrating the applicability of the method to larger molecules.

show abstract

Spin–Orbit Couplings for Nonadiabatic Molecular Dynamics at the ΔSCF Level

Cited by 6 publications

References 100 publications

Birth of the Hydrated Electron via Charge-Transfer-to-Solvent Excitation of Aqueous Iodide

Birth of the Hydrated Electron via Charge-Transfer-to-Solvent Excitation of Aqueous Iodide

The ΔSCF method for non-adiabatic dynamics of systems in the liquid phase

Calculations of Excited Electronic States by Converging on Saddle Points Using Generalized Mode Following

Contact Info

Product

Resources

About