Transformation of potential energy surfaces for estimating isotopic shifts in anharmonic vibrational frequency calculations

被引:20
作者
Meier, Patrick [1 ]
Oschetzki, Dominik [1 ]
Berger, Robert [2 ]
Rauhut, Guntram [1 ]
机构
[1] Univ Stuttgart, Inst Theoret Chem, D-70569 Stuttgart, Germany
[2] Tech Univ Darmstadt, Clemens Schopf Inst Organ Chem & Biochem, D-64287 Darmstadt, Germany
关键词
SELF-CONSISTENT-FIELD; PLESSET PERTURBATION-THEORY; FRANCK-CONDON PRINCIPLE; ECKART AXIS CONDITIONS; POLYATOMIC-MOLECULES; WAVE-FUNCTIONS; FORCE-FIELDS; EFFICIENT CALCULATION; ROTATING AXES; SPECTRA;
D O I
10.1063/1.4874849
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
A transformation of potential energy surfaces (PES) being represented by multi-mode expansions is introduced, which allows for the calculation of anharmonic vibrational spectra of any isotopologue from a single PES. This simplifies the analysis of infrared spectra due to significant CPU-time savings. An investigation of remaining deviations due to truncations and the so-called multi-level approximation is provided. The importance of vibrational-rotational couplings for small molecules is discussed in detail. In addition, an analysis is proposed, which provides information about the quality of the transformation prior to its execution. Benchmark calculations are provided for a set of small molecules. (C) 2014 AIP Publishing LLC.
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页数:12
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