Multiplet ligand-field theory using Wannier orbitals

We demonstrate how ab initio cluster calculations including the full Coulomb vertex can be done in the basis of the localized, generalized Wannier orbitals which describe the low-energy density functional (LDA) band structure of the infinite crystal, e.g. the transition metal 3d and oxygen 2p orbitals. The spatial extend of our 3d Wannier orbitals (orthonormalized Nth order muffin-tin orbitals) is close to that found for atomic Hartree-Fock orbitals. We define Ligand orbitals as those linear combinations of the O 2p Wannier orbitals which couple to the 3d orbitals for the chosen cluster. The use of ligand orbitals allows for a minimal Hilbert space in multiplet ligand-field theory calculations, thus reducing the computational costs substantially. The result is a fast and simple ab initio theory, which can provide useful information about local properties of correlated insulators. We compare results for NiO, MnO and SrTiO3 with x-ray absorption, inelastic x-ray scattering, and photoemission experiments. The multiplet ligand field theory parameters found by our ab initio method agree within ~10% to known experimental values

The Cerium volume collapse: Results from the LDA+DMFT approach

The merger of density-functional theory in the local density approximation (LDA) and many-body dynamical mean field theory (DMFT) allows for an ab initio calculation of Ce including the inherent 4f electronic correlations. We solve the DMFT equations by the quantum Monte Carlo (QMC) technique and calculate the Ce energy, spectrum, and double occupancy as a function of volume. At low temperatures, the correlation energy exhibits an anomalous region of negative curvature which drives the system towards a thermodynamic instability, i.e., the $\gamma$-to-$\alpha$ volume collapse, consistent with experiment. The connection of the energetic with the spectral evolution shows that the physical origin of the energy anomaly and, thus, the volume collapse is the appearance of a quasiparticle resonance in the 4f-spectrum which is accompanied by a rapid growth in the double occupancy.Comment: 4 pages, 3 figure

Non-resonant driving of H atom with broken time-reversal symmetry

The dynamics of atomic hydrogen placed in a static electric field and illuminated by elliptically polarized microwaves is studied in the range of small field amplitudes where perturbation calculations are applicable. For a general configuration of the fields any generalized time-reversal symmetry is broken and, as the classical dynamics is chaotic, the level statistics obeys the random matrices prediction of Gaussian unitary ensemble.Comment: 4 pages, 2 figures, accepted for publication in J. Phys.

Pulmonary Hypertension in Patients with Chronic Fibrosing Idiopathic Interstitial Pneumonias

Background Pulmonary hypertension (PH) is a common finding in patients with chronic fibrosing idiopathic interstitial pneumonias (IIP). Little is known about the response to pulmonary vasodilator therapy in this patient population. COMPERA is an international registry that prospectively captures data from patients with various forms of PH receiving pulmonary vasodilator therapies. Methods We retrieved data from COMPERA to compare patient characteristics, treatment patterns, response to therapy and survival in newly diagnosed patients with idiopathic pulmonary arterial hypertension (IPAH) and PH associated with IIP (PH-IIP). Results Compared to patients with IPAH (n = 798), patients with PH-IIP (n = 151) were older and predominantly males. Patients with PH-IIP were treated predominantly with phosphodiesterase-5 inhibitors (88% at entry, 87% after 1 year). From baseline to the first follow-up visit, the median improvement in 6MWD was 30 m in patients with IPAH and 24.5 m in patients with PH-IIP (p = 0.457 for the difference between both groups). Improvements in NYHA functional class were observed in 22.4% and 29.5% of these patients, respectively (p = 0.179 for the difference between both groups). Survival rates were significantly worse in PH-IIP than in IPAH (3-year survival 34.0 versus 68.6%; p<0.001). Total lung capacity, NYHA class IV, and mixed-venous oxygen saturation were independent predictors of survival in patients with PH-IIP. Conclusions Patients with PH-IIP have a dismal prognosis. Our results suggest that pulmonary vasodilator therapy may be associated with short-term functional improvement in some of these patients but it is unclear whether this treatment affects survival

Static vs. dynamical mean field theory of Mott antiferromagnets

Studying the antiferromagnetic phase of the Hubbard model by dynamical mean field theory, we observe striking differences with static (Hartree-Fock) mean field: The Slater band is strongly renormalized and spectral weight is transferred to spin-polaron side bands. Already for intermediate values of the interaction $U$ the overall bandwidth is larger than in Hartree-Fock, and the gap is considerably smaller. Such differences survive any renormalization of $U$. Our photoemission experiments for Cr-doped V$_2$O$_3$ show spectra qualitatively well described by dynamical mean field theory.Comment: 6 pages, 5 figures - one figure added and further details about quasiparticle dispersio

Electronic Structure of Paramagnetic V_2O_3: Strongly Correlated Metallic and Mott Insulating Phase

LDA+DMFT, the computation scheme merging the local density approximation and the dynamical mean-field theory, is employed to calculate spectra both below and above the Fermi energy and spin and orbital occupations in the correlated paramagnetic metallic and Mott insulating phase of V_2O_3. The self-consistent DMFT equations are solved by quantum Monte Carlo simulations. Room temperature calculations provide direct comparison with experiment. They show a significant increase of the quasiparticle height in comparison with the results at 1160 K. We also obtain new insights into the nature of the Mott-Hubbard transition in V_2O_3. Namely, it is found to be strikingly different from that in the one-band Hubbard model due to the orbital degrees of freedom. Furthermore we resolve the puzzle of the unexpectedly small Mott gap in Cr-doped V_2O_3.Comment: 14 pages, 22 figure

Momentum resolved spin dynamics of bulk and surface excited states in the topological insulator Bi2Se3\mathrm{Bi_{2}Se_{3}}

The prospective of optically inducing a spin polarized current for spintronic devices has generated a vast interest in the out-of-equilibrium electronic and spin structure of topological insulators (TIs). In this Letter we prove that only by measuring the spin intensity signal over several order of magnitude in spin, time and angle resolved photoemission spectroscopy (STAR-PES) experiments is it possible to comprehensively describe the optically excited electronic states in TIs materials. The experiments performed on $\mathrm{Bi_{2}Se_{3}}$ reveal the existence of a Surface-Resonance-State in the 2nd bulk band gap interpreted on the basis of fully relativistic ab-initio spin resolved photoemission calculations. Remarkably, the spin dependent relaxation of the hot carriers is well reproduced by a spin dynamics model considering two non-interacting electronic systems, derived from the excited surface and bulk states, with different electronic temperatures.Comment: 5 pages and 4 figure

Heterogeneity in Blood Pressure Response to 4 Antihypertensive Drugs: A Randomized Clinical Trial

Importance: Hypertension is the leading risk factor for premature death worldwide. Multiple blood pressure-lowering therapies are available but the potential for maximizing benefit by personalized targeting of drug classes is unknown. Objective: To investigate and quantify the potential for targeting specific drugs to specific individuals to maximize blood pressure effects. Design, Setting, and Participants: A randomized, double-blind, repeated crossover trial in men and women with grade 1 hypertension at low risk for cardiovascular events at an outpatient research clinic in Sweden. Mixed-effects models were used to assess the extent to which individuals responded better to one treatment than another and to estimate the additional blood pressure lowering achievable by personalized treatment. Interventions: Each participant was scheduled for treatment in random order with 4 different classes of blood pressure-lowering drugs (lisinopril [angiotensin-converting enzyme inhibitor], candesartan [angiotensin-receptor blocker], hydrochlorothiazide [thiazide], and amlodipine [calcium channel blocker]), with repeated treatments for 2 classes. Main Outcomes and Measures: Ambulatory daytime systolic blood pressure, measured at the end of each treatment period. Results: There were 1468 completed treatment periods (median length, 56 days) recorded in 270 of the 280 randomized participants (54% men; mean age, 64 years). The blood pressure response to different treatments varied considerably between individuals (P <.001), specifically for the choices of lisinopril vs hydrochlorothiazide, lisinopril vs amlodipine, candesartan vs hydrochlorothiazide, and candesartan vs amlodipine. Large differences were excluded for the choices of lisinopril vs candesartan and hydrochlorothiazide vs amlodipine. On average, personalized treatment had the potential to provide an additional 4.4 mm Hg-lower systolic blood pressure. Conclusions and Relevance: These data reveal substantial heterogeneity in blood pressure response to drug therapy for hypertension, findings that may have implications for personalized therapy. Trial Registration: ClinicalTrials.gov Identifier: NCT02774460

Preliminary Feeding Assessments for Asiatic Garden Beetle, Maladera formosae (Coleoptera: Scarabaeidae), Grubs and Adults

The Asiatic garden beetle, Maladera formosae (Brenske) (syn. M. castanea [Arrow]), is an annual white grub species that was unintentionally introduced from east Asia to North America in 1921 in New Jersey, and has since spread to at least 25 states and two Canadian provinces. Grub populations in the Great Lakes region have recently emerged as significant early-season pests of field crops, particularly field corn, grown in sandy soils. Asiatic garden beetle has also recently become established in other regions including Alabama. Prior research on this species was conducted mainly in the 1930s in horticultural and turfgrass systems of New York and New Jersey. In this study, we document Asiatic garden beetle preference and performance on previously un-investigated food resources, in populations from Ohio and Alabama. The objectives of these experiments were to a) understand if grubs show preference to potential diet choices present in a typical Ohio corn-soybean rotation, and gained mass when provided a single diet, and b) to conduct a preliminary assessment on the development, survival, and fecundity of field-collected beetles on different diets present in suburban Alabama. In general, grubs were more likely to be found at corn and marestail and they significantly increased in body mass when subjected to those diets. However, they were also able to survive and gain mass when provided soybean, crop residues or bare soil. Adults consumed more rose flower petals than floral tissue of white clover and Queen Anne’s lace. In no-choice trials, only females that were fed a diet of rose petals laid eggs, and diet consumption rates were similar among males and females. These findings provide insight into the feeding behaviors of Asiatic garden beetle grubs and adults collected from novel environments