The ABC (atom-bond connectivity) index of a graph is defined as half the sum of the matrix elements of its ABC matrix. It was introduced
by Estrada *et al. *(2017) to model the enthalpy of formation of alkanes (Zheng
*et al. *2023).

# ABC Index

## See also

ABC Matrix## Explore with Wolfram|Alpha

## References

Estrada, E. "The ABC Matrix."*J. Math. Chem.*

**55**, 1021-1033, 2017.Zheng, R.; Su, P.; and Jin. S. "Arithmetic-Geometric Matrix of Graphs and Its Applications."

*Appl. Math. Comput.*

**42**, 127764, 1-11, 2023.

## Cite this as:

Weisstein, Eric W. "ABC Index." From *MathWorld*--A Wolfram Web Resource. https://mathworld.wolfram.com/ABCIndex.html