Excition splitting

Azoaromatic polymers shows many characteristics e.g. excitation splitting of dichoric absorption, optical activity, photoresponsiveness, photorefractivity and NLO properties [62]. 

Towler M D, Flood R Q and Needs R J 2000 Minimum principles and level splitting in quantum Monte Carlo excitation energies application to diamond Phys. Rev. B 62 2330-7... 

Figure B3.4.17. When a wavepacket comes to a crossing point, it will split into two parts (schematic Gaussians). One will remain on the same adiabat (difFerent diabat) and the other will hop to the other adiabat (same diabat). The adiabatic curves are shown by fidl lines and denoted by ground and excited die diabatic curves are shown by dashed lines and denoted 1, 2.

Here (p, cp2Q and (p2 are the waveflmctions of tire non-excited and excited molecules if tliere is no interaction between tliem. In tire case we consider tire molecules do interact and as a result the dimer exlribits properties different from Arose of tire monomers it comprises. In particular, tire energy level of tire excited state is different from tire monomer—it is split into two states ... 

In the excited states for the same potential, the log modulus contains higher order terms mx(x, x, etc.) with coefficients that depend on time. Each term can again be decomposed (arbitrarily) into parts analytic in the t half-planes, but from elementary inspection of the solutions in [261,262] it turns out that every term except the lowest [shown in Eq. (59)] splits up equally (i.e., the/ s are just 1 /2) and there is no contribution to the phases from these temis. Potentials other than the harmonic can be treated in essentially identical ways. 

Figure 13. Vibrational levels for the first-excited electronic state of HD2 calculated [8] using split basis (SB) technique with A(R) = tp/2 coordinate-transformation (CT) treatment with A(R) — tp/2 Eq. (A. 14) with A (R) — y(p, 9, tp). Shown by the longer line segments are the levels assuming different values in two sets of calculations.

When Va varied within the interval 1-8 cm the tunneling splitting was found to depend nearly linearly on Fj, in agreement with the semiclassical model of section 3.5 [see eq. (3.92)], and the prefactor AjA ranged from 0.1 to 0.3, indicating nonadiabatic tunneling. Since this model is one-dimensional, it fails to explain the difference between splittings in the states with the [Pg.127]

We can further conclude that the success of the Cl-Singles method often depends critically on the chosen basis set. Diffuse (Rydberg-like) excited states usually require the addition of one or two diffuse functions to a split-valence basis set. 

In an ociiihcOraJ field (he free-ion ground F lerm of a d ion is split into an A and two T terms which, along with the excited T(P) term (Fig. A), give rise to the possibility of three spin-allowed d-d transitions of which (he one of lowest eneigy is a direct measure of the ciystal field splitting, A or 10 Dq ... 

Splitting the h2 operator into an excitation and de-excitation part, h2 = e, d, allows the propagator to be written as two property vectors times an inverse matrix, often called... 

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