Princeton group working out
water’s molecular mysteries
Posted November 13, 2013
Water molecules seem simple, containing three atoms – two hydrogens and one oxygen. But this basic structure gets complicated as these molecules interact. Strong attractions between the molecules’ atoms lead to water’s high boiling point. Water molecules’ shape and organization in ice make it an unusual solid, with less density than the liquid state.
Because of these challenges and water’s importance for chemistry, biology, the environment and novel energy sources, researchers want a handle on how groups of water molecules behave around each other.
The Princeton University team of Robert A. DiStasio Jr., Biswajit Santra and Roberto Car has been studying water in depth on supercomputers. This year, they’re probing its microscopic structure with an ASCR Leadership Computing Challenge (ALCC) grant of time on Argonne National Laboratory supercomputers.
The idea is to fill in details about how water molecule groups interact, then make that information widely available. Armed with this knowledge, researchers may be able to build greener energy sources, such as aqueous batteries, and better understand a host of chemical reactions that occur in liquid water.
Battery technologies often depend on the use of organic solvents. As a renewable resource, water costs less and is nontoxic and nonflammable. Water-based battery materials could be non-acidic and have a lower environmental footprint, making disposal easier, DiStasio says.
The water puzzle
If you zoom in on a single water molecule, understanding what’s going on is straightforward, DiStasio says. “Researchers can tell you anything you want to know about a single molecule, or even a few.” With a single molecule of water researchers can use highly accurate, quantum mechanical equations to model the details of both the nuclei and electrons of the component atoms.