Dear Rattakorm 

You could use Discover Studio, Material Studio, MAPS and YASARA for your purpose, However you also could check NWChem  for fully open source platform.

Hope it help 

Cheers 

You can use Gromacs with an external soft of QM, if you decire to make a simulation of QMMM. For instance, Gamess, Gaussian:

http://wwwuser.gwdg.de/~ggroenh/qmmm.html

http://wwwuser.gwdg.de/~ggroenh/qmmm.html

Thank you everyone a lot for the answer.

@MD SHARIF KHAN - could you pick a specific one for me that easiest to use?

If you able to use paid one then you could chose Discover Studio or Material Studio both are from same organisation and good in resources. However, In case of open source NWChem is seems to a good platform and its have a lot of resources. However, before selecting software It is good to think about your requirements, It is convenient to select one which one could full fill your pre and post processing easily.

Hope its help 

Cheers 

I'd recommend you try AMBER's SANDER module. It's included in the free AmberTools package that you can download here, and it includes number of semiemprirical QM methods, as well as interfaces with QM specialized software such as GAUSSIAN, GAMESS, NWCHEM, etc. 

HTH.

http://ambermd.org

Why do not you need to run your simulations based on forcefield methods? What are the advantages of the QM?? Do you want to generate new forcefield parameters? Do not you trust to the forcefields, distributed b....? If you need us to help you in this issue please let us know your answers...