Journal ArticleDOI
Anharmonic vibrational spectroscopy calculations with electronic structure potentials: comparison of MP2 and DFT for organic molecules
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TLDR
In this paper, anharmonic spectra of several organic molecules such as allene, propyne, glycine, and imidazole were computed from ab initio MP2 potentials and DFT potentials based on commonly used BLYP and B3LYP functionals.Abstract:
Density functional theory (DFT) technique is the most commonly used approach when it comes to computation of vibrational spectra of molecular species. In this study, we compare anharmonic spectra of several organic molecules such as allene, propyne, glycine, and imidazole, computed from ab initio MP2 potentials and DFT potentials based on commonly used BLYP and B3LYP functionals. Anharmonic spectra are obtained using the direct vibrational self-consistent field (VSCF) method and its correlation-corrected extension (CC-VSCF). The results of computations are compared with available experimental data. It is shown that the most accurate vibrational frequencies are obtained with the MP2 method, followed by the DFT/B3LYP method, while DFT/BLYP results are often unsatisfactory.read more
Citations
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Ab initio calculation of vibrational absorption and circular dichroism spectra using density functional force fields
TL;DR: In this paper, the unpolarized absorption and circular dichroism spectra of the fundamental vibrational transitions of the chiral molecule, 4-methyl-2-oxetanone, are calculated ab initio using DFT, MP2, and SCF methodologies and a 5S4P2D/3S2P (TZ2P) basis set.
Journal ArticleDOI
Vibrational self-consistent field calculations for spectroscopy of biological molecules: new algorithmic developments and applications
TL;DR: This review describes the vibrational self-consistent field method and its other variants for computing anharmonic vibrational spectroscopy of biological molecules and investigates the scaling of computational effort for large biological molecules with many vibrational modes.
Journal ArticleDOI
Theoretical spectroscopy of floppy peptides at room temperature. A DFTMD perspective: gas and aqueous phase
TL;DR: Room temperature DFT-based molecular dynamics simulations for the purpose of interpreting finite temperature infrared spectra of peptides of increasing size and complexity are reviewed, in terms of temperature-dependent conformational dynamics and flexibility, and vibrational anharmonicities.
Journal ArticleDOI
Vibrational Spectra of α-Glucose, β-Glucose, and Sucrose: Anharmonic Calculations and Experiment
Brina Brauer,Madeleine Pincu,Victoria Buch,Ilana Bar,John P. Simons,R. Benny Gerber,R. Benny Gerber +6 more
TL;DR: The VSCF method is used to assess the role of anharmonic effects in the spectra of the sugars in isolation and in the solid state and to discuss the spectroscopic accuracy of potentials from different electronic structure methods.
Journal ArticleDOI
Energy transport via coordination bonds.
TL;DR: The observed strong cross-peak amplifications and a correlation between the energy transport time and the intermode distance, the distance between atom pairs on which vibrational excitations predominantly reside, demonstrate an applicability of the RA 2DIR method for structural interrogation of transition metal complexes.
References
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TL;DR: In this article, a semi-empirical exchange correlation functional with local spin density, gradient, and exact exchange terms was proposed. But this functional performed significantly better than previous functionals with gradient corrections only, and fits experimental atomization energies with an impressively small average absolute deviation of 2.4 kcal/mol.
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Development of the Colle-Salvetti correlation-energy formula into a functional of the electron density
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Journal ArticleDOI
General atomic and molecular electronic structure system
Michael W. Schmidt,Kim K. Baldridge,Jerry A. Boatz,Steven T. Elbert,Mark S. Gordon,Jan H. Jensen,Shiro Koseki,Nikita Matsunaga,Kiet A. Nguyen,Shujun Su,Theresa L. Windus,Michel Dupuis,John A. Montgomery +12 more
TL;DR: A description of the ab initio quantum chemistry package GAMESS, which can be treated with wave functions ranging from the simplest closed‐shell case up to a general MCSCF case, permitting calculations at the necessary level of sophistication.
Journal ArticleDOI
Ab Initio Calculation of Vibrational Absorption and Circular Dichroism Spectra Using Density Functional Force Fields
TL;DR: In this article, the unpolarized absorption and circular dichroism spectra of the fundamental vibrational transitions of the chiral molecule, 4-methyl-2-oxetanone, are calculated ab initio using DFT, MP2, and SCF methodologies and a 5S4P2D/3S2P (TZ2P) basis set.