Triplet Electronic States of Acetylene:
Synergy Between Theory and Experiment

Here we will describe some of our work on the electronic states of acetylene, C₂H₂, focusing particularly on its triplet states. This work has resulted in a very healthy interplay between theory and experiment to answer several controversial or unctertain aspects of acetylene's electronic structure.

1. Introduction and Background
2. Potential Difficulties for ³B₂ Predictions
3. New Challenges from Experiment
4. Zeeman Anticrossing Spectra Anomalies
5. Conclusions