Terahertz-pulse driven modulation of electronic spectra: Modeling electron-phonon coupling in charge-transfer crystals

Turning on Organic Radical Emitters

“…Therefore, we can consider whether |⟨ D⟩| can be determined using the total molecular energies obtained from quantum chemistry methods. Indeed, an effective molecular electron-electron repulsion energy U ef f can be estimated as the difference between the ionization potential and the electron affinity of the PLY radical, 104,105 U ef f = E(P LY − ) + E(P LY + ) − 2E(P LY ), where E is the DFT ground state radical total energy in the different oxidation states. Similarly, the effective on-site energy ε ef f can be obtained from the radical ionization potential as ε ef f = E(P LY ) − E(P LY + ), thus leading to the effective |D| ef f = U ef f + 2ε ef f .…”

Theoretical-computational modeling of charge transfer and intersystem crossing reactions in complex chemical systems

“…In ISC reactions the R / P transition virtually coincides with a QC spin eigenstate transition and hence, introducing the (electrons) spin eigenstates s R s P (with s R s s P ), the perturbed electronic-spin eigenstates F e,R s R and F e,P s P as obtained neglecting any magnetic interaction and provided within PMM by diagonalizing the perturbed electronic Hamiltonian matrix given by eqn (18) and (19) for the R and P spin eigenstate respectively, can be used as proper diabatic electronic-spin states. Therefore, the electronic transition energy can be simply obtained by DU e ¼ U e,P À U e,R where U e,R , U e,P are eigenvalues of the electronic Hamiltonian matrix corresponding to the R and P magnetic state, respectively, and the electronic coupling term corresponding to the R, P element of the perturbed electronic Hamiltonian matrix (including the magnetic interactions) expressed within the diabatic electronicspin basis set, is given by H e,R,P y hF e,R s R |Ĥ so |F e,P s P i ¼ h † RH so h P (27) whereĤ so is the spin-orbit Hamiltonian operator,H so is the corresponding matrix and h R h P the unit vectors representing F e,R s R and F e,P s P within the same basis set used to express the spin-orbit matrix (i.e. the unperturbed basis set).…”

“…[1][2][3] As a matter of fact typical possibly non-BO phenomena such as Charge-Transfer (CT), energy transfer or spin transitions (Intersystem Crossing, ISC) play a key role in many of the processes occurring, for example, in biological systems or material science [4][5][6][7][8][9][10][11] and hence their modeling is of great intellectual and practical relevance. Nowadays a number of elegant theories and efficient algorithms are available for studying in great detail such effects in the dynamics of small to medium-sized molecular systems [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] both in the gas-phase and even taking into account coupling with external baths (see for example 28 and references therein cited). However the modeling of non-BO effects in complex molecular systems at atomistic level, e.g.…”