Chemical Physics Letters, Vol.429, No.1-3, 286-288, 2006
On the definition of the effectively unpaired electron density matrix: A similarity measure approach
The mathematical concepts of similarity and distance in metric spaces are used to relate Takatsuka et al. and Head-Gordon definitions of the effectively unpaired electron density matrix. This approach opens the possibility of new suitable definitions of this quantity to given purposes. (c) 2006 Elsevier B.V. All rights reserved.