There are 40 hydrogen bonds between the protein and the RNA in the preprocessed starting structure. From these force fields, the ff19SB+OL3 and AMOEBA closely match the initial hydrogen bond count. Like the Ago2 systems, in all the nonpolarizable force fields, there are on average more observed hydrogen bonds between the protein and the RNA than in the crystal structure. In the O3P water simulations where there are structural integrity issues, the number of hydrogen bonds drops by 9.