search

crest-lab / crest

CREST - A program for the automated exploration of low-energy molecular chemical space.
https://crest-lab.github.io/crest-docs/
GNU Lesser General Public License v3.0
198 stars 42 forks source link

Defaults equivalence: v. 2.12 and v.3.01 #304

Open aslozada opened 4 months ago

aslozada commented 4 months ago

Hi,

I carried out a test to compare the results of Conformational Sampling between versions 2.12 and 3.01 of CREST. In this test, the calculation is performed sequentially on models of linear alkanes, CnH2n+2 (n=2,10). As can be seen in the figure below, the number of conformers in version 2.12 is always greater than the quantities obtained with version 3.0.1. On the other hand, the energy values in both cases are in the range of (0.0, 6.0) kcal/mol (as shown in the file crest.energies). The execution of CREST, in both cases, was in standard command-line mode: crest file.xyz --gfn2 -T 8 (v.2.12), and crest file.xyz --gfn2 -T 8 (v.3.0.1).

g1

I would be very grateful for any information.

Are the default values the same in both versions (parameters such as Vbias, ewin, etc.)?

pprcht commented 4 months ago

Hi, The defaults are the same in both versions, the difference is only the backend implementation of the xTB Hamiltonians. In the 3.0+ versions we got rid of the I/O communication layer between xtb and CREST and instead are using the tblite implementation. Both implementations of the Hamiltonian are consistent except for the implicit solvation, although very minor differences may occur due to the different code structure. However, I believe the newer versions to be a bit "cleaner", i.e. part of what you are seeing here is likely from false positive cases.