Tag Archives: energy barrier

Liquid calcium carbonate

Geologist Adam Wallace reports in ‘Science’ that calcium carbonate has a dense liquid phase

Computer simulations could help scientists make sense of a recently observed and puzzling wrinkle in one of nature’s most important chemical processes. It turns out that calcium carbonate — the ubiquitous compound that is a major component of seashells, limestone, concrete, antacids and other naturally and industrially produced substances — may momentarily exist in liquid form as it crystallizes from solution.

“Our simulations suggest the existence of a dense liquid form of calcium carbonate,” said co-corresponding author Adam Wallace, an assistant professor of geological sciences in UD’s College of Earth, Ocean, and Environment who conducted the research while a postdoctoral researcher at the Lawrence Berkeley National Laboratory. “This is important because it is an as-yet unappreciated component of the carbon cycle.” (more…)

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Forcing the Molecular Bond Issue

New and Improved Model of Molecular Bonding from Researchers at Berkeley Lab’s Molecular Foundry

Material properties and interactions are largely determined by the binding and unbinding of their constituent molecules, but the standard model used to interpret data on the formation and rupturing of molecular bonds suffers from inconsistencies. A collaboration of researchers led by a scientist at the U.S Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) has developed a first-of-its-kind model for providing a comprehensive description of the way in which molecular bonds form and rupture. This model enables researchers to predict the “binding free energy” of a given molecular system, which is key to predicting how that molecule will interact with other molecules.

“Molecular binding and unbinding events are much simpler than we have been led to believe from the standard model over the past decade,” says Jim DeYoreo, a scientist with the Molecular Foundry, a DOE nanoscience center at Berkeley Lab who was one of the leaders of this research. “With our new model, we now have a clear means for measuring one of the most important parameters governing how materials and molecules bind together.” (more…)

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