Group V dimers on Si(0Â 0Â 1): Can they act as Lewis bases?

The interaction between BF3, a Lewis acid, and group V dimers on Si(0 0 1) is studied with density functional theory calculations. It is found that there is only a small interaction between the dimers and BF3, and that the lone pairs of the group V dimers are too diffuse and spherical to act as electron donors.