Phosphorescence parameters for platinum (II) organometallic chromophores: A study at the non-collinear four-component Kohn–Sham level of theory

A theoretical characterization of the phosphorescence decay traces of a prototypical platinum (II) organic chromophore has been conducted. The phosphorescence wavelength and radiative lifetime are predicted to equal 544 nm and 160 μs, respectively. The third triplet state is assigned as participator in the intersystem crossing and is predicted to have a phosphorescence decay rate 12 times larger than that of the lowest triplet state. This result offers an explanation for the experimentally observed double exponential decay. The self-consistent field (SCF) optimization of the electron density was accomplished only after introducing algorithmic improvements, now incorporated in the Dirac program.