Valence and molecular orbital theories

Cesium's Off‐the‐Map Valence Orbital

The Td -symmetric [CsO4 ]+ ion, featuring Cs in an oxidation state of 9, is computed to be a minimum. Cs uses outer core 5s and 5p orbitals to bind the oxygen atoms. The valence Cs 6s orbital lies too high to be involved in bonding, and contributes to Rydberg levels only. From a molecular orbital perspective, the bonding scheme is reminiscent of XeO4 : an octet of electrons to bind electronegat...

Probing Transient Valence Orbital Changes with Picosecond Valence-to-Core X-ray Emission Spectroscopy

We probe the dynamics of valence electrons in photoexcited [Fe(terpy)2]2+ in solution to gain deeper insight into the Fe-ligand bond changes. We use hard X-ray emission spectroscopy (XES), which combines element specificity and high penetration with sensitivity to orbital structure, making it a powerful technique for molecular studies in a wide variety of environments. A picosecond-time-resolve...

Diffractive molecular orbital tomography

High harmonic generation in the interaction of femtosecond lasers with atoms and molecules opens the path to molecular orbital tomography and to probe the electronic dynamics with attosecondÅngström resolutions. Molecular orbital tomography requires both the amplitude and phase of the high harmonics. Yet the measurement of phases requires sophisticated techniques and represents formidable chall...

Molecular-orbital studies via satellite-free x-ray fluorescence: Cl K absorption and K-valence-level emission spectra of chlorofluoromethanes.

Spin-state splittings, highest-occupied-molecular-orbital and lowest-unoccupied-molecular-orbital energies, and chemical hardness.

It is known that the exact density functional must give ground-state energies that are piecewise linear as a function of electron number. In this work we prove that this is also true for the lowest-energy excited states of different spin or spatial symmetry. This has three important consequences for chemical applications: the ground state of a molecule must correspond to the state with the maxi...