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Computations of the Raman optical activity via the sum‐over‐states expansions
Author(s) -
Bouř Petr
Publication year - 2001
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 - 10.1002/1096-987x(200103)22:4<426::aid-jcc1013>3.0.co;2-#
Subject(s) - raman spectroscopy , computation , statistical physics , computational chemistry , physics , mathematics , chemistry , quantum mechanics , algorithm
A computationally convenient and reasonably accurate scheme of computation of the Raman Optical Activity (ROA) is presented and tested on model examples. Electromagnetic tensors were obtained using the sum‐over‐states (SOS) methodology, while their nuclear derivatives were estimated through numerical differentiation. An origin dependence of the results was overcome by a distributed origin gauge transformation. Becke‐3LYP functional and corresponding Kohn–Sham orbitals are used for the excited states. The method was compared to a benchmark coupled‐perturbed (CP) calculation on formamide and a standard ROA spectral simulation and experiment for α‐pinene. Spectra of four standard peptide conformations (α‐helix, 3 10 ‐helix, coil, and β‐sheet) were simulated with smaller fragments and compared to previous experimental observations. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 426–435, 2001