The year 1970 has been suggested as a starting date for the "third age of quantum chemistry," in which theory takes on not only qualitative but also quantitative value. In fact, each of the years 1960, 1970, 1972, and 1977 is of historical value in the unraveling of the structure and energetics of the CH(2) molecule, methylene. What took place for methylene, namely the establishment of credibil...

We have performed ab initio calculations of the frequency shift induced by a static electric field on the cesium clock hyperfine transition. The calculations are used to find the frequency shifts due to blackbody radiation. Our result (δν/E = −2.26(2) × 10Hz/(V/m)) is in good agreement with early measurements and ab initio calculations performed in other groups. We present arguments against rec...

The challenges specific to the development of computational chemistry software are discussed. Selected solutions are presented, including examples of algorithmic optimizations and improved load-balancing for parallel calculations. A software framework for development of new quantum-chemical algorithms is proposed. Key design points are discussed. Optimization techniques are briefly described. I...

Here, we present just a collection of beans (JACOB): an integrated batch-based framework designed for the rapid development of computational chemistry applications. The framework expedites developer productivity by handling the generic infrastructure tier, and can be easily extended by user-specific scientific code. Paradigms from enterprise software engineering were rigorously applied to creat...

We present here the computational chemistry methods our group uses to investigate the physical and chemical properties of nanoporous materials and adsorbed fluids. We highlight the multiple time and length scales at which these properties can be examined and discuss the computational tools relevant to each scale. Furthermore, we include the key points to considerupsides, downsides, and possibl...

Increasingly, understanding complex problems in computational chemistry requires the use of several applications as components of computational workflows. Unfortunately, this process is severely hindered by a lack of data interchange standards. The eCCP and eMinerals UK eScience projects are developing a framework to facilitate the interoperability of such applications. Data sets are serialised...

268 © Copyright ChE Division of ASEE 2006 In many engineering curricula it is difficult to cover the fundamental concepts that are required to provide all students with an optimum base for the solution development of new problems and applications. Although this task is daunting, replacing the learning and understanding of fundamental concepts with starting parameters and a list of equations to ...

A series of chalcone-based macrocyclic ethers have been synthesized. These macrocyclic ethers contain polyether as well as extended conjugation to the benzene ring to function as fluorescent sensor for cations. The modeling studies show that the chalcone part of the receptors remains partially out of plane from the polyether part and the keto moiety of the receptors always directed outwardly in...