 The mutually consistent field (MCF) method  had introduced the idea of self-consistent fragment calculations in their embedding potential, which was later used with some modifications in various methods including FMO.There had been other methods related to FMO including the incremental correlation method by H. Stoll (1992).Later, other methods closely related to FMO were proposed including the kernel energy method of L. Huang and the electrostatically embedded many-body expansion by E. Dahlke,
S. Hirata and later M. Kamiya suggested approaches also very closely related to FMO.