GROMACS version:
GROMACS modification: Yes/No
The solvent viscosity can be varied by changing the solvent mass. This can be done by varying parameters in the forcefield. I am trying to vary the viscosity of water molecules. What files in forcefield folder should one vary? I tried adding a separate column next to the forcefield, but it seems to not work. The atom names are mentioned in other .itp folders such as atomtypes.atp and ffnonbodend.itp.
Modiefied TIP3P.itp file:
[ moleculetype ]
; molname nrexcl
SOL 2
[ atoms ]
; id at type res nr residu name at name cg nr charge
#ifdef _FF_CHARMM
1 OT 1 SOL OW 1 -0.834 16.0
2 HT 1 SOL HW1 1 0.417 1.0
3 HT 1 SOL HW2 1 0.417 1.0
#endif
Masses of OT is defined as 15.99 in ffnonbonded.itp and atomtypes.atp. Should the masses be varied there too for varying the mass in total?