Hi everybody, Could anyone tell me how to get free energy with constrained MD? The input file in &MOTION like this: &CONSTRAINT &COLLECTIVE COLVAR 1 INTERMOLECULAR TARGET [angstrom] 1.2 TARGET_GROWTH [angstrom] 0.01 TARGET_LIMIT [angstrom] 3.0 &END COLLECTIVE &END CONSTRAINT Thank you in advance. Best regards, sun