# Vibrational progression of an OLED phosphorescent emitter

**NOTE** that this example was made with a previous version of ADF. Since the technical defaults have changed in 2014, screenshots of the menu panels and the actual results will be different with the current ADF modeling suite.

Triplet harvesting in OLEDs by tranisition metal complexes increased the maximum efficiency from 25% to 100%. Singlet excitons are rapidly converted to triplet excited states and fast phosphorescence can be achieved by strong spin-orbit coupling.

In this example we calculate the frequencies of the T_{1} and S_{0} state of Pt(4,6-dFppy)(acac) to determine the vibronic fine structure from the Franck-Condon factors. We compare with the experimental results from the Yersin group (Chem. Phys. Lett. 468 (2009) 46-51).

You can download the sample input files, which have been kindly provided with the figures by Mr. Mori (Ryoka).

To calculate the overlap of the vibronic wave functions we first need to calculate the frequencies of the two electronic states involvedr, finally followed by the Franck-Condon calculation. So we have three steps:

- Optimize the lowest singlet state (S
_{0}) and calculate frequencies - Optimize the lowest triplet state (T
_{1}) and calculate frequencies - Calculation of the Franck-Condon Spectrum

You can start straight away with the example input files or read further to learn how to set up these two calculations for your own complexes.