2 Method
The processes of the calculation were as follows:
(1) Generate initial conformations of probes with
Confab;10
(2) Use Crest to call xtb to do batch structural optimization under the
GFN2-xTB method,11 and
then call isostat in Molclus12 program to screen out
several conformations with the lowest energy for next step;
(3) Use Molclus to call
ORCA13 to perform
optimization and vibrational frequency analysis on the conformations
generated from step (2) under
PBE0/def2-TZVP,14,
15 and then single point energy and
TDDFT calculation under wB2GP-PLYP/def2-TZVP so as to obtain the free
energy with high
precision.16,
17