Premium
Modeling of coupled proton transfers by analytic functions
Author(s) -
Duan Xiaofeng,
Scheiner Steve
Publication year - 1992
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.560440713
Subject(s) - proton , exponential function , ab initio , chemistry , coupling (piping) , quadratic equation , function (biology) , computational chemistry , simple (philosophy) , potential energy , atomic physics , molecular physics , transfer (computing) , physics , quantum mechanics , mathematical analysis , materials science , mathematics , philosophy , geometry , epistemology , evolutionary biology , metallurgy , biology , parallel computing , computer science
Potential energy surfaces are generated by ab initio calculations for the transfer of two protons in the pentameric chains (H 2 O ·· H 2 O ·· H 2 OH + ·· OH 2 ·· OH 2 ) and (H 3 N ·· H 3 N ·· H 3 NH + NH 3 ·· NH 3 ). These surfaces are then fit by the sum of (a) two functions, each of which reproduces the transfer potential of a single proton plus (b) a function that models the coupling between the two protons. Several candidates are tested for the latter coupling function. A simple linear dependence upon the motion of the two protons reproduces the full two–dimensional surface to an accuracy of some 1 kcal/mol. The popular quadratic function provides a poorer approximation as also do exponential and Coulombic‐type functions. © 1992 John Wiley & Sons, Inc.