Here we propose a new notation for the hypercoordinated multicenter units formed by electron-rich elements in Fig. . Our notation is different from that used by Crabtree and Grabowski , who use the number of ligands, L, that can be understood as the number of bonds, but do not distinguish between ERMBs and EDMBs since previous diagrams. This can be understood because they only considered that linear hypercoordinated multicenter units only applied to ERMBs. The hypercoordinated multicenter units of Fig. can be notated as A(C,E,M), where A refers to the hypercoordinated central atom A and C, E, and M refer to the number of covalent bonds, LEPs, and multicenter bonds (both ERMBs of EDMBs), respectively.