Largely Reduced Grid Densities in a Vibrational Self-Consistent Field Treatment Do Not Significantly Impact the Resulting Wavenumbers

Molecules

Oliver M. D. Lutz²  Bernd M. Rode¹  Günther K. Bonn²  Christian W. Huck² 

[1] Institute of General, Inorganic and Theoretical Chemistry, Center for Chemistry and Biomedicine, University of Innsbruck, Innrain 80-82, Innsbruck 6020, Austria; E-Mail:;Institute of Analytical Chemistry and Radiochemistry, Center for Chemistry and Biomedicine, University of Innsbruck, Innrain 80-82, Innsbruck 6020, Austria; E-Mails:

关键词: VSCF;    grid density;    spectroscopy;    anharmonicity;    MP2;    infrared;    vibrational self-consistent field;    phosphoserine;   

DOI  :  10.3390/molecules191221253

来源: mdpi

【 摘 要 】

Especially for larger molecules relevant to life sciences, vibrational self-consistent field (VSCF) calculations can become unmanageably demanding even when only first and second order potential coupling terms are considered. This paper investigates to what extent the grid density of the VSCF’s underlying potential energy surface can be reduced without sacrificing accuracy of the resulting wavenumbers. Including single-mode and pair contributions, a reduction to eight points per mode did not introduce a significant deviation but improved the computational efficiency by a factor of four. A mean unsigned deviation of 1.3% from the experiment could be maintained for the fifteen molecules under investigation and the approach was found to be applicable to rigid, semi-rigid and soft vibrational problems likewise. Deprotonated phosphoserine, stabilized by two intramolecular hydrogen bonds, was investigated as an exemplary application.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.