Large exciton binding energy Small exciton binding energy Cd 74608 Se 74837 Cd 199 Se 195 Cd 1012 Se 1063 ΔE ΔE ΔE valence valence conduction conduction conduction valence 0 0.5 1 EBE 0 0.5 1 EBE 0 0.5 1 EBE Peh Peh Peh Radius of quantum dotExciton binding energy and electron-hole recombination probability are presented as the two important metrics for investigating effect of dot size on electronhole interaction in CdSe quantum dots. Direct computation of electron-hole recombination probability is challenging because it requires an accurate mathematical description of electron-hole wavefunction in the neighborhood of the electron-hole coalescence point. In this work, we address this challenge by solving the electron-hole Schrodinger equation using the electron-hole explicitly correlated Hartree-Fock (eh-XCHF) method. The calculations were performed for a series of CdSe clusters ranging from Cd 20 Se 19 to Cd 74608 Se 74837 that correspond to dot diameter range of 1 − 20 nm. The calculated exciton binding energies and electron-hole recombination probabilities were found to decrease with increasing dot size. Both of these quantities were found to scale as D −n dot with respect to the dot diameter D. One of the key insights from this study is that the electron-hole recombination probability decreases at a much faster rate than the exciton binding energy as a function of dot size. It was found that an increase in the dot size by a factor of 16.1, resulted in a decrease in the exciton binding energy and electron-hole recombination probability by a factor of 14.4 and 5.5 × 10 6 , respectively.

We present a strategy for the development of electron-proton density functionals in multicomponent density functional theory, treating electrons and selected nuclei quantum mechanically without the Born-Oppenheimer approximation. An electron-proton functional is derived using an explicitly correlated electron-proton pair density. This functional provides accurate hydrogen nuclear densities, thereby enabling reliable calculations of molecular properties. This approach is potentially applicable to relatively large molecular systems with key hydrogen nuclei treated quantum mechanically.

a Results from A. Chakraborty, M. V. Pak, and S. Hammes-Schiffer, J. Chem. Phys. 134, 079902 (2011). NEO-HF is Eq. (10) with g ¼ 0. b All calculations used an STO-2G electronic basis set. NEO calculations used the 5s nuclear basis sets for H, D, and T. c The electron-proton functional used a single geminal function with b ¼ 0:852 a:u: and ¼ 1:962 a:u. These parameters were fixed at their original values. d ÁE ¼ E NEO-DFT À E NEO-HF is the difference in total energies in a.u.

Articles you may be interested inPhotodissociation of (SO2XH) Van der Waals complexes and clusters (XH = C2H2, C2H4, C2H6) excited at 32 040-32090 cm−1 with formation of HSO2 and X Erratum: "Photodissociation of LiFH and NaFH van der Waals complexes: A semiclassical trajectory study" [J.The photodissociation of Li¯FH and Na¯FH van der Waals complexes is studied using Tully's fewest-switches surface-hopping and the natural decay of mixing semiclassical trajectory methods for coupled-state dynamics. The lifetimes of the predissociated excited-state complex ͑exciplex͒, as well as the branching ratio into reactive and nonreactive arrangements and the internal energy distribution of the products are reported at several excitation energies. The semiclassical trajectory methods agree with each other only qualitatively, and the results are strongly dependent on the choice of electronic representation. In general, the lifetime of the LiFH exciplex is shorter and less dependent on the excitation energy than the lifetime of the NaFH exciplex. The semiclassical dynamics of LiFH and NaFH are interpreted in terms of the features of their coupled potential energy surfaces.

Multicomponent density functional theory has been developed to treat systems with more than one type of quantum particle, such as electrons and nuclei, in an external potential. The existence of the exact universal multicomponent density functional in terms of the one-particle densities for each type of quantum particle has been proven. In the present paper, a number of important mathematical properties of the exact universal multicomponent density functional are derived. The expression relating the electron-proton pair density to the one-particle densities leads to an inequality for the potential energy component of the electron-proton correlation functional under well-defined conditions. General inequalities for the kinetic energy correlation functionals and the total electron-proton correlation functional are also derived. The coordinate scaling analysis leads to mathematical inequalities describing the effect of scaled densities on the kinetic, potential, and total energy functionals. The adiabatic connection formula defines the exact electron-proton functional in terms of an adiabatic scaling parameter that smoothly connects the noninteracting system with the fully interacting system. The virial expression provides the relation between the exact kinetic and potential energy functionals for the ground state densities of multicomponent systems. These mathematical relationships provide insight into the fundamental properties of the exact universal multicomponent density functional and serve as a guide for the development of approximate electron-proton density functionals.