David Prendergast

Risk is at the core of criminal recklessness, but its exact constitution comes into focus only in unusual cases. In rethinking criminal law, Larry Alexander and Kimberley Kessler Ferzan say that risk in criminal recklessness ought to be constituted by the subjective belief of the person whose action is being evaluated: the gravity of the harm risked and its probability of resulting is what the person believed it to be, not what it actually was. This means that recklessness can be found in the absence of any “real” risk. This article critiques the authors’ argument for subjective risk in recklessness. They exaggerate the arbitrariness in identifying risk non-subjectively and do not sufficiently acknowledge risk as an inter-subjectively constituted practical concept. Fixing risk subjectively, as advocated by the authors, nonetheless may appear useful for inchoate criminal liability. The article considers and rejects this idea of occasionally subjectivising risk in recklessness.

Risk is at the core of criminal recklessness, but its exact constitution comes into focus only in unusual cases. In rethinking criminal law, Larry Alexander and Kimberley Kessler Ferzan say that risk in criminal recklessness ought to be constituted by the subjective belief of the person whose action is being evaluated: the gravity of the harm risked and its probability of resulting is what the person believed it to be, not what it actually was. This means that recklessness can be found in the absence of any “real” risk. This article critiques the authors’ argument for subjective risk in recklessness. They exaggerate the arbitrariness in identifying risk non-subjectively and do not sufficiently acknowledge risk as an inter-subjectively constituted practical concept. Fixing risk subjectively, as advocated by the authors, nonetheless may appear useful for inchoate criminal liability. The article considers and rejects this idea of occasionally subjectivising risk in recklessness.

The introduction of liquid microjets into soft X-ray absorption spectroscopy enabled the windowless study of liquids by this powerful atom-selective high vacuum methodology. However, weakly interacting liquids produce large vapor backgrounds that strongly perturb the liquid signal. Consequently, solvents and solutions of central importance in chemistry and biology have been inaccessible by this technology. Here we describe a new detection method, upstream detection, which greatly reduces the vapor phase contribution to the X-ray absorption signal while retaining important advantages of liquid microjet sample introduction. The effectiveness of the upstream detection method is demonstrated in this first study of room temperature liquid hydrocarbons: n-nonane and n-decane. Good agreement with first principles' calculations indicates that the eXcited electron and Core Hole theory adequately describes the subtle interactions in these liquids that perturb the electronic structure of the unoccupied states probed in core-level experiments. © 2014 AIP Publishing LLC.

© 2014 Published by Elsevier B.V.Despite much effort, aqueous carbonic acid remains poorly characterized because it is very short-lived. We describe the detection and characterization of aqueous H2CO3 by X-ray absorption spectroscopy, wherein protonation of a bicarbonate solution continuously generates the acid under ambient conditions. Accompanying first principles calculations of the carbon K-edge transitions facilitate spectral assignment and interpretation in terms of the H2CO3 π∗ orbital, which exhibits a small, systematic blueshift relative to that of bicarbonate. These results establish the detailed hydration properties of this short-lived molecule and will thereby facilitate future studies of carbonate chemistry in biological and geological system.

© 2017We present an algorithm and implementation for the parallel computation of exact exchange in Quantum ESPRESSO that exhibits greatly improved strong scaling. QE is an open-source software package for electronic structure calculations using plane wave density functional theory, and supports the use of local, semi-local, and hybrid DFT functionals. Wider application of hybrid functionals is desirable for the improved simulation of electronic band energy alignments and thermodynamic properties, but the computational complexity of evaluating the exact exchange potential limits the practical application of hybrid functionals to large systems and requires efficient implementations. We demonstrate that existing implementations of hybrid DFT that utilize a single data structure for both the local and exact exchange regions of the code are significantly limited in the degree of parallelization achievable. We present a band-pair parallelization approach, in which the calculation of exact exchange is parallelized and evaluated independently from the parallelization of the remainder of the calculation, with the wavefunction data being efficiently transformed on-the-fly into a form that is optimal for each part of the calculation. For a 64 water molecule supercell, our new algorithm reduces the overall time to solution by nearly an order of magnitude.

© 2015 AIP Publishing LLC.Nitrate and nitrite ions are of considerable interest, both for their widespread use in commercial and research contexts and because of their central role in the global nitrogen cycle. The chemistry of atmospheric aerosols, wherein nitrate is abundant, has been found to depend on the interfacial behavior of ionic species. The interfacial behavior of ions is determined largely by their hydration properties; consequently, the study of the hydration and interfacial behavior of nitrate and nitrite comprises a significant field of study. In this work, we describe the study of aqueous solutions of sodium nitrate and nitrite via X-ray absorption spectroscopy, interpreted in light of first-principles density functional theory electronic structure calculations. Experimental and calculated spectra of the nitrogen K-edge XA spectra of bulk solutions exhibit a large 3.7 eV shift between the XA spectra of nitrate and nitrite resulting from greater stabilization of the nitrogen 1s energy level in nitrate. A similar shift is not observed in the oxygen K-edge XA spectra of NO 3 - and NO 2 -. The hydration properties of nitrate and nitrite are found to be similar, with both anions exhibiting a similar propensity towards ion pairing.

© 2015 American Chemical Society.Polarized aluminum K-edge X-ray absorption near edge structure spectroscopy and first-principles calculations were used to probe electronic structure in a series of Al, AlX 2, and AlR 2 coordination compounds. Spectral interpretations were guided by examination of the calculated transition energies and polarization-dependent oscillator strengths, which agreed well with the XANES spectroscopy measurements. Pre-edge features were assigned to transitions associated with the Al 3p orbitals involved in metal-ligand bonding. Qualitative trends in Al 1s core energy and valence orbital occupation were established through a systematic comparison of excited states derived from Al 3p orbitals with similar symmetries in a molecular orbital framework. These trends suggested that the higher transition energies observed for AlX 2 systems with more electronegative X 1- ligands could be ascribed to a decrease in electron density around the aluminum atom, which causes an increase in the attractive potential of the Al nucleus and concomitant increase in the binding energy of the Al 1s core orbitals. For Al and AlH 2 the experimental Al K-edge XANES spectra and spectra calculated using the eXcited electron and Core-Hole approach had nearly identical energies for transitions to final state orbitals of similar composition and symmetry. These results implied that the charge distributions about the aluminum atoms in Al and AlH 2 are similar relative to the AlX 2 and AlMe 2 compounds, despite having different formal oxidation states of +1 and +3, respectively. However, Al was unique in that it exhibited a low-energy feature that was attributed to transitions into a low-lying p-orbital of b 1 symmetry that is localized on Al and orthogonal to the Al plane. The presence of this low-energy unoccupied molecular orbital on electron-rich Al distinguishes its valence electronic structure from that of the formally trivalent compounds AlX 2 and AlR 2. The work shows that Al K-edge XANES spectroscopy can be used to provide valuable insight into electronic structure and reactivity relationships for main-group coordination compounds.