Several past studies reported the use of silver nitrate to control the size of AuNRs Previous studies that span this set of seven precursors indicate achievable rod aspect ratios between 1.5 and 5.0, which is also reflected in the dataset (blue scatter in Fig. ) (two recipes reported aspect ratios ∼ 5.2). Aspect ratios of the nanorods are often controlled by the Ag + amount. Specifically, as the silver nitrate concentration was increased in the controlled experiments of Nikoobakht and El-Sayed, the aspect ratio increased until [AgNO 3 ]=0.00012 M (or log[AgNO 3 ]=-3.92) and decreased after. They attributed this decrease in size to an increased interaction between silver and gold with the surfactant (CTAB) counterions. This trend is qualitatively shown in our dataset, as the maximum 19 aspect ratio for a given silver concentration increases and then decreases around the region of log[AgNO 3 ]=-3.92 (mean-squares quadratic trendline in Fig. ). However, in our case this result is obtained by extracting a variety of synthesis recipes from the literature in contrast to controlled experimental setting of the rest of the precursors' amounts and other synthesis factors.