Supported initially by NIH (USA) grant GM-24893, and later by NIH (USA) grant GM-14312, and NSF (USA) grant MCB05-41633.

Support was also received from the IMASL-CONICET (Argentina), FONCyT-ANPCyT (Argentina) [PAV 22642 / 22672] and from the Universidad Nacional de San Luis (P-328501), Argentina.

The research was conducted using the resources of Pople, a facility of the National Science Foundation Terascale Computing System at the Pittsburgh Supercomputer Center (USA).