Does MDMC OPLS-aa force field follow OPLS-aa properly for the lj/coul interaction when lammps engine is used?

**Description of the error**
In MDMC, there is the option to load the OPLS-aa force field. According to https://pubs.acs.org/doi/10.1021/ja9621760, non-bonded interactions are only applied between atoms separated by three or more bonds, and only 1/2 the interaction strength when separated by three bonds

https://pubs.acs.org/doi/10.1021/ja9621760

In LAMMPS, you'd need to use the https://docs.lammps.org/special_bonds.html option to do this. It is not clear to me that this is being used in the MDMC code via pylammps.

Default for special bonds is "All 3 Lennard-Jones and 3 Coulombic weighting coefficients = 0.0, angle = no, dihedral = no.". To use OPLS correctly, we need something like `special_bonds lj/coul 0.0 0.0 0.5`, not the default.

Individua il codice MDMC che configura LAMMPS tramite pylammps e verifica se viene emesso un comando special_bonds per il campo di forza OPLS-aa. Confronta i pesi configurati di Lennard-Jones e Coulomb con 0.0 0.0 0.5, quindi verifica il comportamento con i test esistenti pertinenti o con un’esecuzione minima di LAMMPS.

Scritto dal modello di indicizzazione a partire dal testo della issue.