A theoretical study of rare-gas diatomic molecules with the generalized-gradient approximation to density functional theory

• Published in: International journal of quantum chemistry Vol. 69; no. 4; pp. 619 - 627
• Main Authors: Patton, David C., Pederson, Mark R.
• Format: Journal Article
• Language: English
• Published: New York John Wiley & Sons, Inc 1998
• ISSN: 0020-7608; 1097-461X
• DOI: 10.1002/(SICI)1097-461X(1998)69:4<619::AID-QUA20>3.0.CO;2-T

Three popular approximations to density functional theory are used to calculate equilibrium bond lengths, atomization energies, and vibrational frequencies of 10 rare‐gas diatomic molecules. We investigated the results for the local density approximation (LDA), the Perdew–Wang 91 generalized‐gradient approximation (GGA–PW91), and the Perdew–Burke–Ernzerhof generalized‐gradient approximation (GGA–PBE) functionals. Calculated results are well converged with respect to basis set and numerical precision. In addition, we studied the effects due to long–range 1/r6 attractions with the London formula and density functional determined atomic polarizabilities and ionization potentials. These calculations indicate that the interaction from the overlap of atomic densities and the long–range van der Waals attraction are both important for correctly predicting the total binding energy. © 1998 John Wiley & Sons, Inc. Int J Quant Chem 69: 619–627, 1998