Dear Ruvini,
In principle, you achieve this change by adjusting your &XC-section to
&XC
# THis sets the correct scaling factors of the different functionals
&XC_FUNCTIONAL B3LYP
&END XC_FUNCTIONAL
&HF
&INTERACTION_POTENTIAL
# CP2K employs by default the Coulomb potential which is not applicable in condensed phase
POTENTIAL_TYPE TRUNCATED
# set it to a value a bit less than half the distance to the nearest neighbor
CUTOFF_RADIUS 4.99
&END INTERACTION_POTENTIAL
&END HF
# For the D3 correction
&VDW_POTENTIAL
POTENTIAL_TYPE PAIR_POTENTIAL
&PAIR_POTENTIAL
TYPE DFTD3
REFERENCE_FUNCTIONAL B3LYP
&END
&END
&END XC
In addition, you should use the B3LYP-optimized pseudopotentials instead of the PADE-versions (Replace GTH-PADE-q* by GTH-B3LYP-q*). Alternatively, you may employ the GTH-HYB-q* pseudopotentials in the POTENTIAL_UZH file.
Beware that calculations with hybrid functionals are significantly more expensive (computation-wise and memory-wise) than calculations on the LDA or GGA level of theory. For that purpose, consider the Auxiliary Density Matrix Method (ADMM) by activating the &AUXILIARY_DENSITY_MATRIX_METHOD section in the &DFT section (see manual
https://manual.cp2k.org/trunk/CP2K_INPUT/FORCE_EVAL/DFT/AUXILIARY_DENSITY_MATRIX_METHOD.html and the regtests for the information on the setup).
Best,
Frederick