A single source has been pinpointed as the culprit for errors given by an important theoretical method.
Fred Manby from the University of Bristol, UK, and colleagues from Germany and the US have carried out a comprehensive analysis of the possible errors in the so-called R12 methods for studying molecular electronic structures.
Methods to study the electronic structure of molecules are important to many scientists. The goal for any calculation is chemical accuracy at low computational cost. R12 methods have shown promise, but have not yet lived up to expectations, generating results with less accuracy than expected.
Recent attention has been focused on successive possible error sources in R12 methods. Manby's results reveal the most important source of error: the form of the correlation factor, which corrects for electron-electron correlation and which until recently had been fixed.
Commenting about future applications, Manby said: 'This work points towards a new generation of high-accuracy methods that are applicable to large chemical systems.'
A J May et al, Phys. Chem. Chem. Phys., 2005, 7, 2710 (DOI: 10.1039/b507781h)