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Basis sets for the evaluation of van der Waals complex interaction energies: Ne–N 2 intermolecular potential and microwave spectrum
Author(s) -
BaranowskaŁączkowska Angelika,
Fernández Berta
Publication year - 2013
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.23483
Subject(s) - van der waals force , basis set , basis (linear algebra) , intermolecular force , atomic physics , chemistry , potential energy surface , van der waals radius , van der waals surface , atom (system on chip) , microwave , physics , computational chemistry , quantum mechanics , molecule , mathematics , geometry , density functional theory , computer science , embedded system , organic chemistry
In order to obtain efficient basis sets for the evaluation of van der Waals complex intermolecular potentials, we carry out systematic basis set studies. For this, interaction energies at representative geometries on the potential energy surfaces are evaluated using the CCSD(T) correlation method and large polarized LPol‐n and augmented polarization‐consistent aug‐pc‐2 basis sets extended with different sets of midbond functions. On the basis of the root mean square errors calculated with respect to the values for the most accurate potentials available, basis sets are selected for fitting the corresponding interaction energies and getting analytical potentials. In this work, we study the Ne–N 2 van der Waals complex and after the above procedure, the aug‐pc‐2–3321 and the LPol‐ds‐33221 basis set results are fitted. The obtained potentials are characterized by T‐shaped global minima at distances between the Ne atom and the N 2 center of mass of 3.39 Å, with interaction energies of −49.36 cm −1 for the aug‐pc‐2–3321 surface and −50.28 cm −1 for the LPol‐ds‐33221 surface. Both sets of results are in excellent agreement with the reference surface. To check the potentials further microwave transition frequencies are calculated that agree well with the experimental and the aV5Z‐33221 values. The success of this study suggests that it is feasible to carry out similar accurate calculations of interaction energies and ro‐vibrational spectra at reduced cost for larger complexes than has been possible hitherto. © 2013 Wiley Periodicals, Inc.