This method has worked quite well for GVB-PP and CCVB calculations in moderately sized basis sets. In this work we will show that the Sano procedure shows undesirable behavior with increasing the size of the AO basis set. This motivates the need for a better behaved alternative. We suggest that finding the antibonding orbital which gives the largest first order perturbation amplitude for exciting an electron pair from a given bonding orbital is a suitable alternative. A range of numerical results confirm this to be the case. These antibonding orbitals can be viewed as a specific instance of orbital specific virtuals. 2 Theory