Marco Caricato

Our research will focus on the theoretical simulation of the photochemistry of complex chromophores with applications in materials and environmental science. To this goal, we will develop 1) accurate electronic structure methods based primarily on coupled cluster theory, and 2) multiscale models that are able to combine multiple levels of theory (quantum and classical mechanics) to describe environmental effects.

1) Electronic structure methods for excited states.

Electronic excited states are still a challenge for computational chemistry: accurate wavefunction methods are too expensive for large molecules of interest in many practical applications, while efficient density functional methods still provide results that are too system dependent. Therefore, reliable theoretical predictions and interpretation of the photochemistry of large molecular compounds are difficult. Our group will investigate physically motivated approximations that can reduce the computational cost of wavefunction methods while preserving their accuracy, and will develop efficient computed code to perform practical calculations.

2) Multiscale models.

Interesting chemical processes often do not occur in a vacuum. The environment may exert a strong influence on these processes, and its effects should be included in theoretical simulations. Unfortunately, the amount of molecules involved in the environment is too large to be treated at a high level of theory (think, for instance, of a solvent). However, environmental effects can be treated as perturbations on the wavefunction of the main compounds. Hence, these effects can be introduced at lower, more manageable levels of theory. Multiscale models do just that: the entire system is divided in layers, each treated at a reasonable level of theory while appropriately introducing coupling terms between layers. Our group will develop multiscale methods that couple multiple quantum, classical, and continuum methods that will feel each other's influence self-consistently by means of electronic embedding potentials.

3) Simulation of molecular properties.

The methods developed in our group, as well as more standard computational tools, will be applied to the study of systems in materials, energy, and environmental science. Our aim is to provide interpretation to outstanding questions posed by experiments as well as provide predictions that may point towards new research directions.