COBRAMM SimPhoNy Wrapper

SimPhoNy wrapper for the COBRAMM engine developed at UNIBO.

The COBRAMM SimPhoNy wrapper enables modelling the electronic (UV-VIS) linear absorption (LA) spectrum of a solvated neutral molecule in its singlet ground state. The QM/MM COBRAMM engine developed at UNIBO is employed. COBRAMM performs hybrid QM/MM calculations by linking the Gaussian (QM) and Amber (MM) software packages.

An explicit atomistic MM model (Amber force field) is used for the solvent, while an explicit atomistic QM model (DFT/TDDFT) is used for the solvated chromophore. A classical equilibration of the solvent-solute system followed by a QM/MM optimization with Wigner sampling and QM/MM excited state calculations is employed to generate the LA spectrum and its bandshape. Vibrational progressions are not considered at this stage. The wrapper makes available to the user three different schemes of increasing complexity and computational time (Low, Medium, High) that do set parameters for MD simulations (boxsize, cutoff, initial optimization steps, time step of the MD run, heating time, time of the final equilibration steps) and QM/MM simulations (solvent droplet radius, mobile layer radius, number of samples produced in the Wigner sampling) of increasing complexity, accuracy and computational cost. Have a look at the documentation for further information and the workflow details.

Contact: Marco Garavelli (UNIBO)