High resolution electron momentum spectroscopy of the valence orbitals of water

Communication: Avoiding unbound anions in density functional calculations

“…Generally, HF densities are not as accurate as those of approximate density functional calculations, 41 because the latter include correlation albeit approximately. However, for anions this is formally untrue, since a truly self-consistent approximate DFT calculation in the infinite basis limit will lose some fraction of an electron to the continuum, so that the bound density will not even integrate to the correct number of electrons.…”

“…may give poor densities when using small basis sets, 41 to overcome this problem, we use Dunning's augmented correlationconsistent pVTZ (AVTZ) basis set. 42,43 Structures of neutral molecules and molecular ions are optimized with selfconsistent Kohn-Sham-DFT and non-scaled zero-point vibrational correction with the same functional is added.…”

Calculation of Stark resonance parameters for valence orbitals of the water molecule

“…The molecular orbitals for water from [21] have been compared to experimental electron spectroscopy studies [23], and also to more sophisticated calculations, and were found to give reasonable agreement with observations. For further studies of state-of-the art spectrocopy and calculations we refer the reader to [24].…”

Time-resolved electron(e,2e)momentum spectroscopy: Application to laser-driven electron population transfer in atoms

“…The validity of this planewave approximation can also be verified experimentally by comparing (e, 2e) measurements for different energies of the incident electrons (see, e.g., Refs. [28,35,37,38]). Since we are interested in the motion of valence electrons, whose momentum distributions are typically concentrated within the range of 0.0-2.0 a.u., this approximation is adequate for our purposes.…”

“…Over the past three decades EMS experimental techniques have steadily improved the precision, accuracy, and detection efficiency of EMS measurements [25,28]. As a result, EMS measurements have been employed as benchmarks for evaluating the accuracy of theoretical calculations of molecular momentum distributions [35,36]. Moreover, owing to the sensitivity of valence electrons to the structure of a molecule, EMS can detect and study modifications of electron momentum densities due to molecular conformation changes [37], molecular pseudorotations [38], multicenter effects [39,40], or vibrations [41,42].…”