Approaches to the solvation of the molecular probe N-methyl-6-quinolone in its excited state.

The molecular probe N-methyl-6-quinolone (MQ) gives experimental access to its local chemical environment, e.g. inside a biomolecule. Using ab initio molecular dynamics (MD), it is possible to simulate the time evolution of the Stokes shift as a function of the actual atomistic coupling to the surrounding hydrogen bond network and thus obtain a comprehensive view of the local environment. In contrast to ground state ab initio MD simulations, the choice of a method for excited state MD is nontrivial. Here, we develop a simple and accurate model for the solvation dynamics of MQ in its first excited state.