A central issue in material science is to obtain understanding of the electronic correlations that control complex materials. Such electronic correlations frequently arise because of the competition of localized and itinerant electronic degrees of freedom. Although the respective limits of well-localized or entirely itinerant ground states are well understood, the intermediate regime that contr...

We report a joint photoelectron spectroscopic and theoretical study of the PtAl(-) and PtAl2(-) anions. The ground state structures and electronic configurations of these species were identified to be C∞v, (1)Σ(+) for PtAl(-), and C2v, (2)B1 for PtAl2(-). Structured anion photoelectron spectra of these clusters were recorded and interpreted using ab initio calculations. Good agreement between t...

The collision-induced electronic energy transfer that occurs when I 2 in the E(0 g ϩ) ion-pair electronic state collides with ground electronic state I 2 has been investigated. We prepare I 2 in single rotational levels in vϭ0 of the E state using two-color double resonance laser excitation. The resulting emission spectrum shows that the nearby (⌬T e ϭϪ385 cm Ϫ1) D(0 u ϩ) electronic state is po...

A central issue in material science is to obtain understanding of the electronic correlations that control complex materials. Such electronic correlations frequently arise due to the competition of localized and itinerant electronic degrees of freedom. While the respective limits of well-localized or entirely itinerant ground states are well-understood, the intermediate regime that controls the...

We discuss pump-probe signals from the wavepackets which are simultaneously generated on both the ground and excited electronic states by weak optical pulses shorter in duration than a vibrational period. A classical model of localized ground state bleaching and excited state population of the internuclear geometries where the photon energy matches the electronic energy gap predicts the pump an...

New imidazole-based energetic molecules (1,4-dinitroimidazole, 2,4-dinitroimidazole, 1-methyl-2,4-dinitroimidazole, and 1-methyl-2,4,5-trinitroimidazole) are studied both experimentally and theoretically. The NO molecule is observed as a main decomposition product from the above nitroimidazole energetic molecules excited at three UV wavelengths (226, 236, and 248 nm). Resolved rotational spectr...

We study the spin-ordering and the magnon collective modes of the twodimensional Wigner crystal state at strong magnetic fields. Our work is based on the Hartree-Fock approximation for the ground state and the timedependent Hartree-Fock approximation for the collective modes. We find that the ground state is ferromagnetic, i.e., that all spins are aligned at T = 0 even when the electronic g-fac...

performances of electronic and mechanical draft control systems on a mf399 tractor were the objectives of the study to be evaluated and compared under field conditions. hence, the effects of two draft control systems (mechanical and electronic) under four ground speed levels and three set values of draft levels on rear wheel slippage, fuel consumption, compressive force within the top link and ...

We re-examine the electronic response of the Chevrel phase Mo6S8 upon Mg intercalation. The ground state Mo6S8 is metallic and exhibits strongly localized electronic screening of Mg(2+) ions. This localized screening cloud effectively shields the 2+ charge carried by Mg ions on the length scale of one unit cell and facilitates Mg ion diffusion.

The charge redistribution upon photoexcitation is investigated for a series of pyrene photoacids to better understand the driving force behind excited-state proton-transfer processes. The changes in electric dipole for the lowest two electronic transitions ( (1)L b and (1)L a) are measured by Stark spectroscopy, and the magnitudes of charge transfer of the protonated and deprotonated states are...