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Accuracy of distributed multipoles and polarizabilities: Comparison between the LoProp and MpProp models
Author(s) -
Söderhjelm P.,
Krogh J. W.,
Karlström G.,
Ryde U.,
Lindh R.
Publication year - 2007
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.20632
Subject(s) - multipole expansion , dipole , moment (physics) , chemistry , ab initio quantum chemistry methods , ab initio , polarizability , spherical multipole moments , computational chemistry , fast multipole method , atomic physics , molecule , physics , quantum mechanics , organic chemistry
Localized multipole moments up to the fifth moment as well as localized dipole polarizabilities are calculated with the MpProp and the newly developed LoProp methods for a total of 20 molecules, predominantly derived from amino acids. A comparison of electrostatic potentials calculated from the multipole expansion obtained by the two methods with ab initio results shows that both methods reproduce the electrostatic interaction with an elementary charge with a mean absolute error of ∼1.5 kJ/mol at contact distance and less than 0.1 kJ/mol at distances 2 Å further out when terms up to the octupole moments are included. The polarizabilities are tested with homogenous electric fields and are found to have similar accuracy. The MpProp method gives better multipole moments unless diffuse basis sets are used, whereas LoProp gives better polarizabilities. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007