Lowering of the complexity of quantum chemistry methods by choice of representation

The complexity of the standard hierarchy of quantum chemistry methods is not invariant to the choice of representation. This work explores how the scaling of common quantum chemistry methods can be reduced using real-space, momentum-space, and time-dependent intermediate representations without introducing approximations. We find the scalings of exact Gaussian basis Hartree--Fock theory, second-order M{\o}ller-Plesset perturbation theory, and coupled cluster theory (specifically, linearized coupled cluster doubles and the distinguishable cluster approximation with doubles) to be $\mathcal{O}(N^3)$, $\mathcal{O}(N^3)$, and $\mathcal{O}(N^5)$ respectively, where $N$ denotes system size. These scalings are not asymptotic and hold over all ranges of $N$

SURVEY OF CATALYST AND REDUCTANT EFFECTS ON OXORHENIUM CATALYZED DEOXYDEHYDRATION OF GLYCOLS

Sustainable and renewable carbon sources are of great interest for long term succession of humankind. The sugars and polyols derived from cellulosic biomass offer such a sustainable feedstock considering cellulosic biomass is the largest carbon commodity on Earth. Selective deoxygenation of these sugars and polyols may well provide a feedstock for the synthesis of fine chemicals and fuels. Deoxydehydration (DODH) is one of the selective deoxygenation methods for upgrading sugars and polyols to higher energy alkenes using an oxometal catalyst and a stoichiometric reductant. In this report several aspects for the oxorhenium catalyzed DODH of polyols are examined. An alternate realm of reductants are introduced for the oxorhenium catalyzed DODH of glycols. The commercially available ammonium perrhenate (APR) is employed along with zero-valent elements zinc, iron, manganese, or carbon as reductant for the effective DODH of various glycols. These elemental reductants and their oxidized products remain heterogeneous in the reaction mixture allowing for their simple separation. Stable, ligated, cationic dioxorhenium(V) compounds of the form RevO2Ln+ are demonstrated to be proficient pre-catalysts for the DODH of glycols with assorted reductants. The tetrapyridine dioxorhenium(V) complexes [ReO2py4]Cl and [ReO2py4]PF6 (py = pyridine) are demonstrated to be proficient pre-catalysts for the DODH of glycols with sodium sulfite, zinc, and benzyl alcohol (BnOH). In addition, the commercially available bis-triphenylphosphine(TPP) iodo dioxorhenium(V) complex (ReO2(TPP)2I) is established to be capable of BnOH driven DODH of glycols. Mechanistic aspects of [ReO2py4]+ DODH of glycols with BnOH are probed. There is an apparent second order dependence on the oxorhenium complex. This second order dependence on rhenium is attributed to a bimolecular turn over limiting step involving one rhenium coordinating and activating BnOH for reduction of the second rhenium which has been oxidized through alkene extrusion from a rhenium-glycolate. The DODH reaction is also found to have a negative pseudo-order in the glycol and is attributed to inactive polyglycol rhenium species. The addition of catalytic concentrations of additional ligands such as pyridine or triphenylphosphine oxide accelerate the reaction and are likely involved in shifting the equilibrium towards the rhenium monoglycol and away from the polyglycol

PC-SEAPAK user's guide, version 4.0

PC-SEAPAK is designed to provide a complete and affordable capability for processing and analysis of NOAA Advanced Very High Resolution Radiometer (AVHRR) and Nimbus-7 Coastal Zone Color Scanner (CZCS) data. Since the release of version 3.0 over a year ago, significant revisions were made to the AVHRR and CZCS programs and to the statistical data analysis module, and a number of new programs were added. This new version has 114 procedures listed in its menus. The package continues to emphasize user-friendliness and interactive data analysis. Additionally, because the scientific goals of the ocean color research being conducted have shifted to larger space and time scales, batch processing capabilities were enhanced, allowing large quantities of data to be easily ingested and analyzed. The development of PC-SEAPAK was paralled by two other activities that were influential and assistive: the global CZCS processing effort at GSFC and the continued development of VAX-SEAPAK. SEAPAK incorporates the instrument calibration and support all levels of data available from the CZCS archive

Dworkin\u27s Perfectionism

In this essay, we shall interpret Dworkin\u27s constitutional theory in light of three varieties of perfectionism: (1) the idea that government should undertake a formative project of inculcating civic virtues and encouraging responsibility in the exercise of rights; (2) the idea that we should interpret the American Constitution so as to make it the best it can be; and (3) the idea that we should defend a Constitution-perfecting theory that would secure not only procedural liberties essential for democratic self-government but also substantive liberties essential for personal self-government. We shall identify three gaps left by Dworkin\u27s work and sketch how we have sought to fill those gaps in the spirit of his work through developing a mild form of constitutional perfectionis

Respecting Freedom and Cultivating Virtues in Justifying Constitutional Rights

What’s new in the long-standing debate between civic republicans and liberals about how best to understand and justify rights? This article picks up the thread with political philosopher Michael Sandel’s recent, internationally-renowned book, Justice: What’s the Right Thing To Do? The article evaluates the sharp contrasts his book draws between justice as cultivating virtues and justice as respecting freedom, using his example of contemporary arguments for and against opening up civil marriage to same-sex couples. Sandel contends that “liberal neutrality” and a public square denuded of religious arguments and convictions are impossible on this issue. Drawing on Aristotle, he contends that it is necessary to engage in substantive moral argument about marriage as a social institution, the virtues it honors and rewards, and whether gay and lesbian unions are worthy of the honor and recognition that, in our society, state-sanctioned marriage confers. Arguments rooted in freedom to choose one’s marital partner or in the right to equal access to marriage will not suffice. In this article, we offer a close reading of the Massachusetts marriage opinion, Goodridge v. Department of Public Health (2003), and the California marriage opinion, In re Marriage Cases (2008), to support our argument that Sandel draws too stark a dichotomy between virtue-based and freedom-based arguments about justice (and, in turn, between civic republicanism and liberalism), and that both strands feature in these opinions. Arguments about why marriage matters as a social institution fruitfully complement arguments about why marriage matters from an individual rights perspective, although the latter properly constrain certain appeals to religious arguments about civil marriage. We conclude with a brief consideration of how these arguments play out in the recent federal district court opinion, Perry v. Schwarzenegger, which held Proposition 8 (amending the California constitution to bar same-sex marriage) unconstitutional

Gaussian and plane-wave mixed density fitting for periodic systems

We introduce a mixed density fitting scheme that uses both a Gaussian and a plane-wave fitting basis to accurately evaluate electron repulsion integrals in crystalline systems. We use this scheme to enable efficient all-electron Gaussian based periodic density functional and Hartree-Fock calculations

Some Questions for Civil Society-Revivalists

This Article raises some questions for proponents of reviving civil society as a cure for many of our nation\u27s political, civic, and moral ills (whom McClain and Fleming designate as civil society-revivalists ). How does civil society serve as seedbeds of virtue and foster self-government? Have liberal conceptions of the person corroded civil society and undermined self-government? Does the revivalists\u27 focus on the family focus on the right problems? Have gains in equality and liberty caused the decline of civil society? Should we revive civil society or a civil society? Would a revitalized civil society support democratic self-government or supplant it? McClain and Fleming largely agree with the revivalists that it would be a good thing to revive civil society, but they raise doubts about whether its revival can reasonably be expected to accomplish what its proponents hope for it, e.g., moral renewal, civic renewal, and strengthening the bonds of citizenship. They suggest that civil society is at least as important for securing what we call deliberative autonomy -enabling people to decide how to live their own lives-as for promoting deliberative democracy -preparing them for participation in democratic life. Working within the tradition of political liberalism, and guided by key feminist and civic republican commitments, McClain and Fleming also sketch their own views concerning the proper roles and regulation of civil society in our morally pluralistic constitutional democracy