Laser-field-induced surface-hopping method for the simulation and control of ultrafast photodynamics

Abstract

We present the semiclassical laser field induced surface hopping method for the simulation and control of coupled electron-nuclear dynamics in complex molecular systems including all degrees of freedom. Our approach is based on the Wigner representation of quantum mechanics. The combination of the molecular dynamics "on the fly" employing quantum initial conditions with the surface hopping procedure allows for the treatment of the electronic transitions induced by the laser field. Our semiclassical approach reproduced accurately exact quantum dynamics in a two electronic state model system. We demonstrate the scope of our method on the example of the optimal pump-dump control of the trans-cis isomerization of a prototypical Schiff base molecular switch. Our results show that selective photochemistry can be achieved by shaped laser pulses which open new dynamical pathways by suppressing the isomerization through the conical intersections between electronic states.

A general method to describe intersystem crossing dynamics in trajectory surface hopping

“…[108,110,[113][114][115][116]119,160] A general on-the-fly implementation of surface hopping in this fashion is available in the SHARC suite. [119,120] In passing we note that similar methodologies using the equivalents of the MCH [163,164] or diagonal [119,[165][166][167][168] electronic bases have also been developed in different contexts to describe other processes, like interactions of electromagnetic fields with molecular dipole moments.…”

“…For very weak SOC, the PES are only weakly deformed and other representations should yield approximately the same results, which justifies the usage of, for example, the MCH representation in some forms of surface hopping including additional couplings. [107,109,163,164] Surface hopping in the diagonal representation Currently there is no quantum chemistry program able to calculate all necessary properties needed for surface hopping in the diagonal basis. While gradients of diagonal states including SOC are already described for semiempirical wavefunctions, [176] no such gradients are available up to now for ab initio electronic structure methods and neither are the corresponding nonadiabatic couplings.…”

Probing the role of excited states in ionization of acetylene

“…The drawback of these approaches is that the initial pumping of the molecule by a laser pulse is not described. In light of this several approaches that describe the explicit interaction with the laser field have been developed [33][34][35].…”

A surface-hopping method for semiclassical calculations of cross sections for radiative association with electronic transitions

“…The surface-hopping method was extended in the last decade for the treatment of arbitrary coupling 31,33,38 . Field-induced couplings were the subject of more studies where the absorption spectra [35][36][37]54 or laser-induced transitions 33,[38][39][40][41] were calculated with the surfacehopping methodology.…”

“…The surface-hopping methodology allows the study of radiative association with electronic transitions to be extended to arbitrary polyatomic system. The surface-hopping method is widely used in the modeling of nonadiabatic molecular processes [31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47] . The idea of this method originally put forward by Bjerre and Nikitin 48 and later advanced by others [49][50][51][52][53] .…”