Rovibrational spectroscopy using a kinetic energy operator in Eckart frame and the multi-configuration time-dependent Hartree (MCTDH) approach

• Verfasst von: Sadri, Keyvan [VerfasserIn]
• Verfasst von: Lauvergnat, David [VerfasserIn]
• Verfasst von: Gatti, Fabien [VerfasserIn]
• Verfasst von: Meyer, Hans-Dieter [VerfasserIn]
• Titel: Rovibrational spectroscopy using a kinetic energy operator in Eckart frame and the multi-configuration time-dependent Hartree (MCTDH) approach
• Verf.angabe: Keyvan Sadri, David Lauvergnat, Fabien Gatti, and Hans-Dieter Meyer
• E-Jahr: 2014
• Jahr: 15 September 2014
• Umfang: 11 S.
• Fussnoten: Gesehen am 07.08.2020
• Titel Quelle: Enthalten in: The journal of chemical physics
• Ort Quelle: Melville, NY : American Institute of Physics, 1933
• Jahr Quelle: 2014
• Band/Heft Quelle: 141(2014,11) Artikel-Nummer 114101, 11 Seiten
• ISSN Quelle: 1089-7690
• DOI: doi:10.1063/1.4895557
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1726651673

Abstract

For computational rovibrational spectroscopy the choice of the frame is critical for an approximate separation of overall rotation from internal motions. To minimize the coupling between internal coordinates and rotation, Eckart proposed a condition [“Some studies concerning rotating axes and polyatomic molecules,” Phys. Rev. 47, 552-558 (1935)] and a frame that fulfills this condition is hence called an Eckart frame. A method is developed to introduce in a systematic way the Eckart frame for the expression of the kinetic energy operator (KEO) in the polyspherical approach. The computed energy levels of a water molecule are compared with those obtained using a KEO in the standard definition of the Body-fixed frame of the polyspherical approach. The KEO in the Eckart frame leads to a faster convergence especially for large J states and vibrationally excited states. To provide an example with more degrees of freedom, rotational states of the vibrational ground state of the trans nitrous acid (HONO) are also investigated.