As an example, consider a doublet electronic state E in cubic symmetry. The symmetric part of E ⊗ E is A 1 + E. Therefore, the state E will couple to vibrational modes Q i transforming as a 1 and e. However, the a 1 modes will result in the same energy shift to all states and therefore do not contribute to any JT splitting. They can therefore be neglected. The result is an E ⊗ e JT effect. This JT effect is experienced by triangular molecules X 3, tetrahedral molecules ML 4, and octahedral molecules ML 6 when their electronic state has E symmetry.