Two starategies of conformational analysis of 1g9w
Comparison of two starategies of conformer screening:
1) Open Babel conformations search - PM7 optimization - DFT
2) Tinker MMFF94 conformers search and optimization - GNF2-xTB single point - DFT
Strategy 1 was proposed in the article I.Y. Kanal, J.A. Keith, G.R. Hutchison,
"A sobering assessment of small-molecule force field methods
for low energy conformer predictions",
Int. J. Quantum Chem., 2018, 118, e25512
Strategy 2 is from our work.
1g9w is a model from the Kanal's article (first in the list of 700 items)
Initial 3D structure was generated from smile by Open Babel.
1). Open Babel confab (default parameters) gives 1865 conformations for 38 s
Mopac PM7 optimization of 1865 conformations gives 326 unique conformers for about 20 h
2). Tinker scan MMFF94 conformers search and optimization gives 489 conformers for 13 m
GNF2-xTB gives single point energies for 269 unique conformers for 1.5 m
The 99 most stable conformers from both PM7 and xTB sets were optimized by DFT/PBE/Λ1.
PM7 set gives 18 unique conformers, xTB set gives 39 unique conformers.
On Figure below, numbers in titles of levels are places of conformes in PM7 and xTB sets
before DFT optimization.
Conformers generators: Confab
from Open Babel and scan from
Tinker (MMFF94 force field).
