A review of the literature about calculating the adsorption properties of arsenic onto mineral models using density functional theory (DFT) is presented. Furthermore, this work presents DFT results that show the effect of model charge, hydration, oxidation state, and DFT method on the structures and adsorption energies for As (oxyhydr)oxide cluster models were calculated using planewave and cluster-model DFT methods.

Six possible complexes of glyphosate (O-PO(OH)-CH2NH2+CH2CO2H) with an Fe-hydroxide dimer were modeled with hybrid molecular orbital/density functional theory calculations to establish the nature of the bonds of glyphosate on goethite (alpha-FeOOH). Monodentate and bidentate coordination of the phosphonate moiety were considered, using three forms of the glyphosate molecule appropriate for different pH ranges: glyphosate with both phosphonate and amino moieties protonated, glyphosate with unprotonated phosphonates, and glyphosate with both unprotonated phosphonates and no hydrogen ion on the amino group. The calculated infrared vibrational modes were compared to experimental values, finding particularly good agreements with the monodentate complexes in all the pH ranges.

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Energy- and angle-resolved intensities are reported for the scattering of argon atoms off the surface of liquid indium just above the melting temperature, for two different argon incident energies. The higher incident energy results show significant energy transfer from argon to liquid atoms, and the angular distribution of scattered argon atoms is relatively sharply peaked near the specular angle. The lower incident energy results show a small amount of energy transfer from liquid atoms to argon atoms, the energy distribution of the scattered argon atoms is nearly thermal, and the angular distribution is much less sharply peaked, although still not completely thermal. Molecular dynamics simulations of these experiments are performed, and most of the results are in reasonable agreement with experiment. Analysis of the simulation trajectories helps to provide a microscopic understanding of the experimental results.

The interactions of HNO(3) and NO(3)(-) with kaolinite surfaces are important in the reaction of airborne clay mineral particles with atmospheric trace gases. Theoretical calculations at the B3LYP/6-311++G(d,p) level were performed on surface clusters of HNO(3) on kaolinite, on monodentate, on bidentate, and on two bridged complex structures of NO(3)(-) on kaolinite and on gas phase and solvated NO(3)(-). The results are compatible with the ranges assigned in the literature for NO(3)(-) on mineral surfaces for the frequency of the vibrational symmetric stretches (ν(1)) and for the low-frequency branch of the asymmetric stretches (ν(3)), with slightly higher frequencies reported for the bridged models. For the higher-frequency branch of the asymmetric stretches measured on kaolinite (Angelini et al.), our calculations match the assigned values for the monodentate surface complex, while predicting an inverse assignment for the frequencies of the bidentate and bridged complexes.

In this laboratory, students calculated the nutritional value of common foods to assess the energy content needed to answer an everyday life application; for example, how many kilometers can an average person run with the energy provided by 100 g (3.5 oz) of beef? The optimized geometries and the formation enthalpies of the nutritional components of the food and their combustion products were calculated using molecular mechanics and a semiempirical method, AM1 or PM3, on the lab computers. These data were used to assess the energy content of common foods and compare with food label information. This general chemistry laboratory was designed for students of food engineering, yet it is applicable to students in any general chemistry course. Groups of students have successfully completed the laboratory as described here. The software was introduced, and the calculations were carried out in two, 2.5 h-long sessions.

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This laboratory was developed by undergraduate students in collaboration with the course instructor as part of a peer-developed and peer-led lab curriculum in a general chemistry course. The goal was to explore the hypothesis that crystal violet lactone was responsible for the thermochromic properties of a sipping straw using a FT-IR for experimental determinations of vibrational frequencies, UV−vis to quantify the color change, and the software packages Spartan and Gaussian 09 for theoretical calculations.