“…Theoretically calculated modes are closed to the experimental results as well as nearly to the ref [21]. Here, it is found here a modification for the reported earlier works [9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24]. The second one popular ring stretching mode, the Kekule ring stretching mode has been observed in the IR and Raman at 1212 and 1210 cm −1 as well as this mode is calculated to be at 1208 cm −1 for 5-aminouracil, but this mode for uracil has been observed in IR and Raman at 1086 cm −1 , this mode is calculated to be at 1086 cm −1 , which is found to be shifted up by ~ 120 cm −1 or increasing up to ~11 % due to the substituted amino (NH 2 ) groups on uracil pyrimidine ring.…”