upward

Triplets

G R Morello, Accurate prediction of emission energies with TD-DFT methods for platinum and iridium OLED materials, J Mol Model 23, 174 (2017)

Spin-orbit interaction

W Barford, R J Bursill, D V Makhov, Spin-orbit interactions between interchain excitations in conjugated polymers, PRB 81, 035206 (2010)