[gmx-users] How fshift array works?

[jia jia]

Dear Gromacs users:
Has anyone got idea how "fshift" array in src/gmxlib/bondfree.c works? I'm
modifing this part to add some new function but could not figure out what's
the function of it.
For exemple, in a common bond potential for atom i and j, it normally end
like
fshift[ki][m]  += fij;
fshift[CENTRAL][m]  -= fij;
I could not find information about this narray in manual and wonder has any
one have some idea about it.
Thank you very much!
Yours
Guang