Born Oppenheimer Molecular Dynamics calculation of the νO-H IR spectra for acetic acid cyclic dimers

3rd International Conference on Mathematical Modeling in Physical Sciences

物理学;数学

Benmalti, Mohamed El Amine^1 ; Krallafa, Abdelghani^2 ; Gaigeot, Marie-Pierre^3

University Abdelhamid Ibn Badis-Mostaganem, Laboratoire de Structure Elaboration et Application Aux Materiaux Moleculaires, Mostaganem

27000, Algeria^1

University of Oran, Laboratoire de Physico-Chimie Macromolculaire, LPCM, Oran

31000, Algeria^2

University of Evry Val D Essonne, LAMBE Lab. Analyse et Modelisation Pour la Biol. et l, EVRY Cedex

91025, France^3

关键词: Ab initio molecular dynamics simulation;    Acetic acid dimers;    Anharmonic couplings;    Born-Oppenheimer;    Born-Oppenheimer molecular dynamics;    Direct and indirect relaxation;    First excited state;    Theoretical modeling;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/574/1/012011/pdf
DOI  :  10.1088/1742-6596/574/1/012011

来源: IOP

【 摘 要 】

Both ab initio molecular dynamics simulations based on the Born-Oppenheimer approach calculations and a quantum theoretical model are used in order to study the IR spectrum of the acetic acid dimer in the gas phase. The theoretical model is taking into account the strong anharmonic coupling, Davydov coupling, multiple Fermi resonances between the first harmonics of some bending modes and the first excited state of the symmetric combination of the two vO-H modes and the quantum direct and indirect relaxation. The IR spectra obtained from DFT-based molecular dynamics is compared with our theoretical lineshape and with experiment. Note that in a previous work we have shown that our approach reproduces satisfactorily the main futures of the IR experimental lineshapes of the acetic acid dimer [Mohamed el Amine Benmalti, Paul Blaise, H. T. Flakus, Olivier Henri-Rousseau, Chem Phys, 320(2006) 267-274.].