TY - JOUR
T1 - Energy-directed tree search
T2 - An efficient systematic algorithm for finding the lowest energy conformation of molecules
AU - Izgorodina, Ekaterina I.
AU - Yeh Lin, Ching
AU - Coote, Michelle L.
PY - 2007
Y1 - 2007
N2 - We present a new systematic algorithm, energy-directed tree search (EDTS), for exploring the conformational space of molecules. The algorithm has been designed to reliably locate the global minimum (or, in the worst case, a structure within 4 kJ mol-1 of this species) at a fraction of the cost of a full conformational search, and in this way extend the range of chemical systems for which accurate thermochemistry can be studied. The algorithm is inspired by the build-up approach but is performed on the original molecule as a whole, and objectively determines the combinations of torsional angles to optimise using a learning process. The algorithm was tested for a set of 22 large molecules, including open- and closed-shell species, stable structures and transition structures, and neutral and charged species, incorporating a range of functional groups (such as phenyl rings, esters, thioesters and phosphines), and covering polymers, peptides, drugs, and natural products. For most of the species studied the global minimum energy structure was obtained; for the rest the EDTS algorithm found conformations whose total electronic energies are within chemical accuracy from the true global minima. When the conformational space is searched at a resolution of 120°, the cost of the EDTS algorithm (in its worst-case scenario) scales as 2N for large N (where N is the number of rotatable bonds), compared with 3N for the corresponding systematic search.
AB - We present a new systematic algorithm, energy-directed tree search (EDTS), for exploring the conformational space of molecules. The algorithm has been designed to reliably locate the global minimum (or, in the worst case, a structure within 4 kJ mol-1 of this species) at a fraction of the cost of a full conformational search, and in this way extend the range of chemical systems for which accurate thermochemistry can be studied. The algorithm is inspired by the build-up approach but is performed on the original molecule as a whole, and objectively determines the combinations of torsional angles to optimise using a learning process. The algorithm was tested for a set of 22 large molecules, including open- and closed-shell species, stable structures and transition structures, and neutral and charged species, incorporating a range of functional groups (such as phenyl rings, esters, thioesters and phosphines), and covering polymers, peptides, drugs, and natural products. For most of the species studied the global minimum energy structure was obtained; for the rest the EDTS algorithm found conformations whose total electronic energies are within chemical accuracy from the true global minima. When the conformational space is searched at a resolution of 120°, the cost of the EDTS algorithm (in its worst-case scenario) scales as 2N for large N (where N is the number of rotatable bonds), compared with 3N for the corresponding systematic search.
UR - http://www.scopus.com/inward/record.url?scp=34248998140&partnerID=8YFLogxK
U2 - 10.1039/b700938k
DO - 10.1039/b700938k
M3 - Article
C2 - 17508083
AN - SCOPUS:34248998140
SN - 1463-9076
VL - 9
SP - 2507
EP - 2516
JO - Physical Chemistry Chemical Physics
JF - Physical Chemistry Chemical Physics
IS - 20
ER -