Whereas the basic ties are known as strong or weak and focus on the strength of the analyzed relationship, simmelian ties are concerned with more than just the strength of the relationship.
[1] Krackhardt developed the concept of a simmelian tie as an alternative to Ronald Burt's structural hole theory.
[1] Simmelian ties are based on the work of, and named after, Georg Simmel, a sociologist who distinguished social triads as an important social structure that's qualitatively different from dyadic relationships in more and more important ways than just the number of people participating.
[1] In his original paper, Krackhardt stressed that restriction, noting that the more cliques one has simmelian ties to, the more constrained one is.
[1] The concept of a simmelian tie is used in the social network analysis.