Added TARGET_ GROWTH, Shake Lagrangian Multipliers only increase without decreasing

[chenyuping6]

Added TARGET_ GROWTH, as the set C-Ag distance becomes shorter, Shake Lagrangian Multipliers only increase without decreasing. This is unreasonable because further adsorption is more likely to occur after the C-Ag bond distance reaches 2.0. Is there something wrong with me? How should I solve it?
&MOTION
&CONSTRAINT
SHAKE_TOLERANCE 1.0E-4
&COLLECTIVE
COLVAR 1
INTERMOLECULAR 1
TARGET [angstrom] 3.00516
TARGET_GROWTH [angstrom*fs^-1] -0.0005
TARGET_LIMIT [angstrom] 1.9
&END COLLECTIVE
&LAGRANGE_MULTIPLIERS
COMMON_ITERATION_LEVELS 1
&END
&END CONSTRAINT