Query regarding slow-growth method in AIMD

[章乐申（粉川桜雪）]

Dear CP2K Developers and Experienced Users,

Hello,

I am new to CP2K and have a question regarding the &MOTION > &CONSTRAINT > &COLLECTIVE section.

I am referencing the official CP2K exercise: "Free Energy Profile of NaCl Dissociation" (https://www.cp2k.org/exercises:2017_ethz_mmm:nacl_free_energy#taskfree_energy_curve_of_nacl_in_water_at_350k). In this tutorial, a fixed restraint on the MYDIST collective variable (CV) is used to perform a PMF calculation .

However, I would like to apply the slow-growth method (i.e., Steered MD) to let the CV gradually increase during the simulation.

I have two specific questions:

1. Is the TARGET_GROWTH keyword the correct approach to implement this? I have included a sample of my input attempt in the attached file. 

2. When setting the initial TARGET value for the CV, must this value exactly match the CV's value calculated from the input structure's coordinates? Or, can I assign it to a desired starting value, even if it differs slightly from the initial configuration?

Thank you very much for your time! I appreciate all of your suggestions.

Yours sincerely, 

Leshen Zhang