Test study on the excitation spectra of the N<inf>2</inf>-He van der Waals molecule

Abstract:

We have performed ab initio fourth-order Møller-Plesset perturbation theory calculations in the framework of the supermolecule approach on the vertical excitation spectra of the weakly bound van der Waals N 2-He dimer. They indicate a "T-shaped" stablest ground N2(X1∑g+)-He(1S) electronic state with a well depth, De, of 21.63 cm-1 at a minimum distance, Re, of 3.44 Å and zero-point vibration correction, Do, of 7.07 cm-1. They also indicate a "T-shaped" stablest excited conformer with Re = 3.25 Å, De = 36.85 cm-1 and Do = 17.06 cm -1 for the N2(B3Πg)-He( 1S) triplet electronic level. In order to investigate the use of less-demanding correlation methods, test density functional theory calculations using the mPW1PW exchange-correlation functional are also presented for comparison.

Año de publicación:

2003

Keywords:

• ab initio calculations
• Van der Waals molecules
• mPW1PW exchange-correlation functional
• Møller-Plesset perturbation theory
• Excitation spectra

Fuente:

scopus