Ionization and Double-Excitations within the Framework of the G-Particle-Hole Hypervirial Equation Method

C. VALDEMORO; D.R. ALCOBA; L.M. TEL

INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY

JOHN WILEY & SONS INC

Lugar: New York; Año: 2012 vol. 112 p. 2965 - 2970

0020-7608

Recently, through the use of one-electron excitation operators, the set of low-lying excited states of several electronic systems was obtained within the framework of the Hermitian Operator method combined with the G-particle-hole Hypervirial equation method [Valdemoro et al., J. Math. Chem. 2012, 50, 492]. The main aim of this article is to extend our study by including higher-order excitations as well as extended ionization and electron affinity operators. Several examples show the convenience of this extension to improve the accuracy of the results in some relevant cases. Through the use of geminal excitations, the algebra of the formal derivations is considerably simplified.