Table 1. Mapping of PEI^a.

chain element	group	atoms	charge	Martini 3 bead type
terminal unit (T)	primary amine	H2N−CH2	0+1	TN6d TQ5d
linear unit (L)	secondary amine	H2C−NH−CH2	0+1	SN4 SQ4p
dendritic unit (D)	tertiary amine	H2C−NCH2−CH2	0+1	SN3a SQ3p

^aAtom to bead mapping of the different chain elements (characterized by their amine group) and corresponding Martini 3 bead types both in their charged and uncharged state. Their respective Lennard-Jones parameters can be found in the Martini 3 force field file on GitHub https://github.com/marrink-lab/martini-force_fields/tree/main/martini_forcefields/regular/v3.0.0/gmx_files.