Non-parametrized functionals with empirical dispersion corrections: A happy match?

The performances of two parametrized functionals (namely B3LYP and B2PYLP) have been compared with those of two non-parametrized functionals (PBE0 and PBE0-DH) on a relatively large benchmark set when three different types of dispersion corrections are applied [namely the D2, D3 and D3(BJ) models]. Globally, the MAD computed using non-parametrized functionals decreases when adding dispersion terms although the accuracy not necessarily increases with the complexity of the model of dispersion correction used. In particular, the D2 correction is found to improve the performances of both PBE0 and PBE0-DH, while no systematic improvement is observed going from D2 to D3 or D3(BJ) corrections. Indeed when including dispersion, the number of sets for which PBE0-DH is the best performing functional decreases at the benefit of B2PLYP. Overall, our results clearly show that inclusion of dispersion corrections is more beneficial to parametrized double-hybrid functionals than to non-parametrized ones. The same conclusions globally hold for the corresponding global hybrids, showing that the marriage between non-parametrized functionals and empirical corrections may be a difficult deal.

SCIENTIFIC LANGUAGE RHETORIC: FROM THE THEORETICAL BASIS TO THE PRODUCTION OF DIDACTIC MATERIAL FOR UNDERGRADUATE CHEMISTRY TEACHING

This work is part of a study that focused on analyzing the contributions of didactic activities related to scientific language rhetoric characteristics aimed at developing students' abilities to identify such characteristics in chemistry scientific texts and critical reading of those texts. In this study, we present the theoretical basis adopted to determine the scientific discourse characteristics and for the production of the didactic material used in those activities. Latour, Coracini and Campanario studies on persuasive rhetorical strategies present in scientific articles aided the production of such material.

Experimental and Theoretical Study of the OH Vibrational Spectra and Overtone Chemistry of Gas-Phase Vinylacetic Acid

In this study we present the gas-phase vibrational spectrum of vinylacetic acid with a focus on the ν = 1−5 vibrational states of the OH stretching transitions. Cross sections for ν = 1, 2, 4 and 5 of the OH stretching vibrational transitions are derived on the basis of the vapor pressure data obtained for vinylacetic acid. Ab initio calculations are used to assist in the band assignments of the experimental spectra, and to determine the threshold for the decarboxylation of vinylacetic acid. When compared to the theoretical energy barrier to decarboxylation, it is found that the νOH = 4 transition with thermal excitation of low frequency modes or rotational motion and νOH = 5 transitions have sufficient energy for the reaction to proceed following overtone excitation.

Theoretical organic chemistry /

Mode of access: Internet.

A text book of dairy chemistry, theoretical and practical, for students of agriculture and dairying /

Includes bibliographical references.

Elements of chemistry : containing the principles of the science : both experimental and theoretical : intended as a text-book for academies, high schools and colleges /

Mode of access: Internet.

System of theoretical and practical chemistry...

Mode of access: Internet.

Fownes' manual of chemistry : theoretical and practical.

Includes index.

An introduction to theoretical and applied colloid chemistry, "the world of neglected dimensions,"

Includes bibliographical references and indexes.

An introduction to theoretical and applied colloid chemistry : "the world of neglected dimensions" /

"This small volume is the literary result of a series of lectures which I gave during the winter of 1913 and 1914 in the United States and Canada upon the invitation of a number of American universities."--Pref.

Scientific researches, experimental and theoretical, in electricity, magnetism, galvanism, electro-magnetism, and electro-chemistry. With copper-plates. #c By William Sturgeon. Published by subscription.

"An abstract of scientific discoveries, inventions, &c., by William Sturgeon, chronologically arranged": p. [33]-51.

Technology of cellulose ethers; a theoretical and practical treatise on the origin, history, chemistry, manufacture, technical application and analysis of the etherified celluloses and carbohydrate carboxylate ehters (esterified cellulose ethers, etherified organic cellulose esters) ...

Paged continuously.

Inorganic general, medical and pharmaceutical chemistry, theoretical and practical; a text-book and laboratory manual, containing theoretical, descriptive, and technological chemistry;

Mode of access: Internet.

Theoretical study on the molecular and electronic properties of some substances used for diabetes mellitus treatment

Diabetes mellitus (DM) is a disease that affects a large number of people, and the number of problems associated with the disease has been increasing in the past few decades. These problems include cardiovascular disorders, blindness and the eventual need to amputate limbs. Therefore, the quality of life for people living with DM is less than it is for healthy people. In several cases, metabolic syndrome (MS), which can be considered a disturbance of the lipid metabolism, is associated with DM. In this work, two drugs used to treat DM, pioglitazone and rosiglitazone, were studied using theoretical methods, and their molecular properties were related to the biological activity of these drugs. From the results, it was possible to correlate the properties of each substance-particularly electronic properties-with the biological interactions that are linked to their pharmacological effects. These results suggest that there are future prospects for designing or developing new drugs based on the correlation between theoretical and experimental properties.