Hi, folks!

I recently used cp2k6.1 to simulate organic molecular crystal systems at a temperature of 100K in the NPT_F ensemble. After the system reached thermal equilibrium, the unit cell volume decreased significantly. However, the optimized structure obtained using VASP changes insignificantly compared to the initial structure. Here are some basic settings of my CP2k. Could anyone help point out which parameter settings are the key issues to influence the cell parameters? Main parameters:

&MD    ENSEMBLE NPT_F ! The length of an integration step    TIMESTEP 1.0 ! The number of MD steps to perform    STEPS  5000 ! The temperature in K used to initialize the velocities    TEMPERATURE 100   &BAROSTAT    PRESSURE 1    TIMECON 100.00   &END BAROSTAT   &THERMOSTAT     TYPE NOSE     &NOSE      TIMECON 100.00    &END NOSE &END THERMOSTAT METHOD QS STRESS_TENSOR ANALYTICAL &DFT   &QS    METHOD gpw    EPS_DEFAULT 1e-12    EXTRAPOLATION ASPC    EXTRAPOLATION_ORDER 3   &END QS   CHARGE 0   MULTIPLICITY 1   BASIS_SET_FILE_NAME  BASIS_MOLOPT   POTENTIAL_FILE_NAME  GTH_POTENTIALS   &MGRID    NGRIDS 4    CUTOFF 400    REL_CUTOFF 60   &END MGRID    &XC_FUNCTIONAL PBE    &END XC_FUNCTIONAL     &VDW_POTENTIAL      POTENTIAL_TYPE PAIR_POTENTIAL      &PAIR_POTENTIAL       PARAMETER_FILE_NAME dftd3.dat       TYPE DFTD3       REFERENCE_FUNCTIONAL PBE       #R_CUTOFF [angstrom] 16      &END PAIR_POTENTIAL     &END VDW_POTENTIAL   &SCF    ADDED_MOS 0    SCF_GUESS ATOMIC    EPS_SCF 1e-06    MAX_SCF 70    &KIND H     BASIS_SET DZVP-MOLOPT-SR-GTH     POTENTIAL GTH-PBE-q1    &END KIND    &KIND C     BASIS_SET DZVP-MOLOPT-SR-GTH     POTENTIAL GTH-PBE-q4    &END KIND    &KIND O     BASIS_SET DZVP-MOLOPT-SR-GTH     POTENTIAL GTH-PBE-q6    &END KIND    &KIND S     BASIS_SET DZVP-MOLOPT-SR-GTH     POTENTIAL GTH-PBE-q6    &END KIND    &KIND N     BASIS_SET DZVP-MOLOPT-SR-GTH     POTENTIAL GTH-PBE-q5    &END KIND