I am creating a parameter file for a small molecule, the cg model of this small molecule contains two virtual sites, I set the mass of these two virtual sites to 0, and when generating the tpr file with gmx grompp, I got the error: atom B5 (Res MOL-0) has mass 0 (state A) / 0 (state B), atom B7 (Res MOL-0) has mass 0 (state A) / 0 (state B). If I set all the mass as default values and can normally generate tpr files. What did I do wrong? This is part of my small molecule parameter file.
I am creating a parameter file for a small molecule, the cg model of this small molecule contains two virtual sites, I set the mass of these two virtual sites to 0, and when generating the tpr file with gmx grompp, I got the error: atom B5 (Res MOL-0) has mass 0 (state A) / 0 (state B), atom B7 (Res MOL-0) has mass 0 (state A) / 0 (state B). If I set all the mass as default values and can normally generate tpr files. What did I do wrong? This is part of my small molecule parameter file.