GROMACS version: 2024
GROMACS modification: Yes/No
Dear Gromacs user,
I am writing about an issue I am facing- the LINCS warnings during alchemical free energy solvation. I want to find out the solvation free energy ( ΔG) of CO2 in a composite system containing ionic liquids and graphene oxide.
When coupling (insertion) of CO₂ into the system using 20 lambda windows with couple lambda0 = none and couple lambda1 = vdw-q , too many LINCs warnings and ultimately the system crashed, and this occurred in the second lambda. This is likely due to strong overlap of CO₂ when the charges are just one, causing instability. However, the reverse process – decoupling of CO₂ (desolvation) (couple lambda0 = vdw-q and couple lambda1 = none) – is stable with no lincs warnings, though it results in a positive ΔG value (see attached .
Note.
The starting conformation is quite stable in terms of density and temperature, having been equilibrated for 10 ns before the alchemical free energy calculations. I am sharing the .mdp file for your reference.
Any suggestions to improve the stability of the system during CO2 solvation would be appreciated.
Thank you
md.mdp (3.7 KB)
