The potential energy surface (PES) for guanine formation from 4-aminoimidazole-5-carbonitrile (AICN) after adding H₂O and cyanogen (NCCN) was determined from quantum chemical calculations using the CBS-QB3 method. Its activation energy was too high for the reaction to occur in the interstellar medium. The PES for the formation of a protonated guanine from AICN by adding H₃O⁺ and NCCN was also determined. Although its overall activation energy was zero, its occurrence in the interstellar gas phase is not likely due to unstable intermediates. When H₂O was added to some reaction steps as a catalyst, their activation barriers were significantly reduced.

使用CBS-QB3方法从量子化学计算中确定了加入H ₂ O和氰化物（NCCN）后由4-氨基咪唑-5-腈（AICN）形成鸟嘌呤的势能面（PES）。它的活化能太高，无法在星际介质中发生反应。还确定了通过添加H ₃ O ⁺和NCCN由AICN形成质子化鸟嘌呤的PES 。尽管其总体活化能为零，但由于不稳定的中间体，它不太可能在星际气相中发生。当将H ₂ O作为催化剂添加到某些反应步骤中时，它们的活化势垒显着降低。