University of Stuttgart

About: University of Stuttgart is a education organization based out in Stuttgart, Germany. It is known for research contribution in the topics: Laser & Finite element method. The organization has 27715 authors who have published 56370 publications receiving 1363382 citations. The organization is also known as: Universität Stuttgart.

Thermotropic Ionic Liquid Crystals

Abstract: The last five years' achievements in the synthesis and investigation of thermotropic ionic liquid crystals are reviewed. The present review describes the mesomorphic properties displayed by organic, as well as metal-containing ionic mesogens. In addition, a short overview on the ionic polymer and self-assembled liquid crystals is given. Potential and actual applications of ionic mesogens are also discussed.

Carbon nanomaterials: production, impact on plant development, agricultural and environmental applications

Abstract: During the relatively short time since the discovery of fullerenes in 1985, carbon nanotubes in 1991, and graphene in 2004, the unique properties of carbon-based nanomaterials have attracted great interest, which has promoted the development of methods for large-scale industrial production. The continuously increasing commercial use of engineered carbon-based nanomaterials includes technical, medical, environmental and agricultural applications. Regardless of the application field, this is also associated with an increasing trend of intentional or unintended release of carbon nanomaterials into the environment, where the effect on living organisms is still difficult to predict. This review describes the different types of carbon-based nanomaterials, major production techniques and important trends for agricultural and environmental applications. The current status of research regarding the impact of carbon nanomaterials on plant growth and development is summarized, also addressing the currently most relevant knowledge gaps.

Fast Hartree-Fock theory using local density fitting approximations

Abstract: Density fitting approximations are applied to generate the Fock matrix in Hartree–Fock calculations. By localizing the orbitals in each iteration and performing separate fits for each orbital the O(N4)caling of the computational effort for the exchange can be reduced to O(N). We also use the Poisson method to replace almost all Coulomb integrals with simple overlaps, an efficient alternative to diagonalization, and dual basis sets such that the Hartree–Fock calculation is performed in a smaller basis than the subsequent treatment of electron correlation. The accuracy and efficiency of the method is demonstrated in calculations with almost 4000 basis functions. The errors introduced by the local approximations on HF and MP2 energies are small compared to those that arise from the density fitting, and the fitting errors themselves (typically 1–10 microhartree per atom) are very small compared, for example, to the effect of basis set variations.