TY - JOUR
T1 - String method in collective variables
T2 - Minimum free energy paths and isocommittor surfaces
AU - Maragliano, Luca
AU - Fischer, Alexander
AU - Vanden-Eijnden, Eric
AU - Ciccotti, Giovanni
N1 - Funding Information:
We thank Weinan E and Weiqing Ren for many useful discussions and comments. This work is partially supported by NSF Grant Nos. DMS02-09959 and DMS02-39625, and by ONR Grant No. N00014-04-1-0565. One of the authors (L.M.) is grateful to COST for partial support under its Action P13. This work was performed while one of the authors (E.V.-E.) was visiting UC Berkeley on a Visiting Professorship position sponsored by the Miller Institute.
PY - 2006
Y1 - 2006
N2 - A computational technique is proposed which combines the string method with a sampling technique to determine minimum free energy paths. The technique only requires to compute the mean force and another conditional expectation locally along the string, and therefore can be applied even if the number of collective variables kept in the free energy calculation is large. This is in contrast with other free energy sampling techniques which aim at mapping the full free energy landscape and whose cost increases exponentially with the number of collective variables kept in the free energy. Provided that the number of collective variables is large enough, the new technique captures the mechanism of transition in that it allows to determine the committor function for the reaction and, in particular, the transition state region. The new technique is illustrated on the example of alanine dipeptide, in which we compute the minimum free energy path for the isomerization transition using either two or four dihedral angles as collective variables. It is shown that the mechanism of transition can be captured using the four dihedral angles, but it cannot be captured using only two of them.
AB - A computational technique is proposed which combines the string method with a sampling technique to determine minimum free energy paths. The technique only requires to compute the mean force and another conditional expectation locally along the string, and therefore can be applied even if the number of collective variables kept in the free energy calculation is large. This is in contrast with other free energy sampling techniques which aim at mapping the full free energy landscape and whose cost increases exponentially with the number of collective variables kept in the free energy. Provided that the number of collective variables is large enough, the new technique captures the mechanism of transition in that it allows to determine the committor function for the reaction and, in particular, the transition state region. The new technique is illustrated on the example of alanine dipeptide, in which we compute the minimum free energy path for the isomerization transition using either two or four dihedral angles as collective variables. It is shown that the mechanism of transition can be captured using the four dihedral angles, but it cannot be captured using only two of them.
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U2 - 10.1063/1.2212942
DO - 10.1063/1.2212942
M3 - Article
AN - SCOPUS:33746255471
SN - 0021-9606
VL - 125
JO - Journal of Chemical Physics
JF - Journal of Chemical Physics
IS - 2
M1 - 024106
ER -