On the equivalence of LIST and DIIS methods for convergence acceleration

Self-consistent field extrapolation methods play a pivotal role in quantum chemistry and electronic structure theory. We here demonstrate the mathematical equivalence between the recently proposed family of LIST methods [J. Chem. Phys. 134, 241103 (2011); J. Chem. Theory Comput. 7, 3045 (2011)] with Pulay's DIIS [Chem. Phys. Lett. 73, 393 (1980)]. Our results also explain the differences in performance among the various LIST methods

Actinide chemistry using singlet-paired coupled cluster and its combinations with density functionals

Singlet-paired coupled cluster doubles (CCD0) is a simplification of CCD that relinquishes a fraction of dynamic correlation in order to be able to describe static correlation. Combinations of CCD0 with density functionals that recover specifically the dynamic correlation missing in the former have also been developed recently. Here, we assess the accuracy of CCD0 and CCD0+DFT (and variants of these using Brueckner orbitals) as compared to well-established quantum chemical methods for describing ground-state properties of singlet actinide molecules. The $f^0$ actinyl series (UO$_2^{2+}$, NpO$_2^{2+}$, PuO$_2^{2+}$), the isoelectronic NUN, and Thorium (ThO, ThO$^{2+}$) and Nobelium (NoO, NoO$_2$) oxides are studied.Comment: 8 page

Funneled angle landscapes for helical proteins

We use crystallographic data for four helical iron proteins (cytochrome c-b₅₆₂, cytochrome c′, sperm whale myoglobin, human cytoglobin) to calculate radial and angular signatures as each unfolds from the native state stepwise though four unfolded states. From these data we construct an angle phase diagram to display the evolution of each protein from its native state; and, in turn, the phase diagram is used to construct a funneled angle landscape for comparison with the topography of its folding energy landscape. We quantify the departure of individual helical and turning regions from the areal, angular profile of corresponding regions of the native state. This procedure allows us to identify the similarities and differences among individual helical and turning regions in the early stages of unfolding of the four helical heme proteins

Cognitive abilities and economic behavior

At the heart of behavioral and experimental economics is the goal to better understand behavior through observation so that economic models can be improved. However, despite the predictions of classical economics, the researcher is often confronted with a great deal of behavioral heterogeneity. One way to approach this heterogeneity is to acknowledge that decision makers differ from each other in fundamental ways and these differences contribute to the differences in observed economic behavior

Choosing To Thrive: Finding Self And Fulfillment Through My Organizational Dynamics Learning Journey

As I sought a better life for myself, making me first in my family in many ways, I struggled to navigate the uncharted territories of college and the workplace far away from home. I was racked with guilt, shame, and fear about the what-ifs, which held me back from living a more authentic life. Various frameworks from the Organizational Dynamics program and other influential experiences have given me the tools to reposition my thinking more purposefully, and to create a vision for living and to uncover my potential as an instrument of change. I describe the powerful moments that propelled me into wanting to thrive and not just survive. I also share my exploration in learning and identifying with the impostor phenomenon experience

Casimir interaction at liquid nitrogen temperature: Comparison between experiment and theory

We have measured the normalized gradient of the Casimir force between Au-coated surfaces of the sphere and the plate and equivalent Casimir pressure between two parallel Au plates at T=77K. These measurements have been performed by means of dynamic force microscope adapted for operating at low temperatures in the frequency shift technique. It was shown that the measurement results at T=77K are in a very good agreement with those at T=300K and with computations at T=77K using both theoretical approaches to the thermal Casimir force proposed in the literature. No thermal effect in the Casimir pressure was observed in the limit of experimental errors with the increase of temperature from T=77K to T=300K. Taking this into account, we have discussed the possible role of patch potentials in the comparison between measured and calculated Casimir pressures.Comment: 18 pages, 8 figures, to appear in Phys. Rev.

Experimental and self-reported measures of risk taking and digit ratio (2D:4D): evidence from a large, systematic study

Using a large (n=704) sample of laboratory subjects, we systematically investigate the links between the digit ratio - a biomarker for pre-natal testosterone exposure - and two measures of individual risk taking: (i) risk preferences over lotteries with real monetary incentives, and (ii) self-reported risk attitude. The digit ratio (also called 2D:4D) is the ratio of the length of the index finger to the length of the ring finger, and we consider both hands’ digit ratios. Previous studies have found that the digit ratio correlates with risk taking in some subject samples, but not others. In our sample, we find that both the right-hand and the left-hand digit ratio are significantly associated with risk preferences: subjects with lower digit ratios tend to choose riskier lotteries. Neither digit ratio, however, is associated with self-reported risk attitude