[gmx-users] Different fudge scaling against the default ones

[Chandan Choudhury]

Dear gmx users,

I see the following lines in the forcefield.itp file of amberGS.ff (gmx
466) (share/gromacs/top/amberGS.ff/) :

;------------------------------------------------------------------------------------------------------------------------------
#define _FF_AMBER
#define _FF_AMBER94

[ defaults ]
; nbfunc        comb-rule       gen-pairs       fudgeLJ fudgeQQ
#ifdef TRUE_AMBERGS_NOVDW14_SCALING
1               2               yes             1.0     0.8333
#else
1               2               yes             0.5     0.8333
#endif

#include "ffnonbonded.itp"
#include "ffbonded.itp"
#include "gbsa.itp"
;------------------------------------------------------------------------------------------------------------------------------

For the defaults section, it seems that it is possible to use different
fudge scaling (1.0, 0.833) against the default ones (0.5, 0.8333).
The default one gets selected automatically. I think one needs add a line in
.mdp file, but I do not know what needs to be done for selection the
different one.

Can anyone shed light on it?

Thanks

Chandan

--
Chandan Kumar Choudhury
National Chemical Laboratory, Pune
India

*"All work and no play makes Jack a dull boy...”*