The performance of the M06 family of exchange-correlation potentials for describing the electronic structure and the Heisenberg magnetic coupling constant (J) is investigated using a set of representative open-shell systems involving two unpaired electrons. The set of molecular systems studied has well defined structures, and their magnetic coupling values are known experimentally. As a general trend, the M06 functional is about equally as accurate as B3LYP or PBE0. The performance of local functionals is important because of their economy and convenience for large-scale calculations; we find that M06-L local functional of the M06 family largely improves over the local spin density approximation and the generalized gradient approximation.
|Original language||English (US)|
|Journal||Journal of Chemical Physics|
|State||Published - 2008|
Bibliographical noteFunding Information:
Financial support has been provided by the Spanish Ministry of Education and Science (Grant Nos. CTQ2005-08459-CO2-01, UNBA05-33-001, and CTQ2005-03222 and “Ramón y Cajal” program (I.P.R.M.)) and by Generalitat de Catalunya (2005SGR-00697). This work has been supported in part by the National Science Foundation under Grant No. CHE-0704974.