Nonlinear optical chromophores containing (porphyrinato)Zn(II), proquinoid, and (terpyridyl)metal(II) building blocks were optimized in a library containing approximately 10(6) structures using the linear combination of atomic potentials (LCAP) methodology. We report here the library design and molecular property optimizations. Two basic structural types of large beta(0) chromophores were examined: linear and T-shaped motifs. These T-shaped geometries suggest a promising NLO chromophoric architecture for experimental investigation and further support the value of performing LCAP searches in large chemical spaces.