A general procedure for obtaining wave functions obeying the virial theorem

✍ Scribed by Michael Lehd; Frank Jensen

• Publisher: John Wiley and Sons
• Year: 1991
• Tongue: English
• Weight: 712 KB
• Volume: 12
• Category: Article
• ISSN: 0192-8651
• DOI: 10.1002/jcc.540120906

✦ Synopsis

The virial theorem for molecules is shown to have two different forms, one employing the energy gradient the other involving the Hellmann-Feynman force. While the former VT can be fulfilled by a uniform scaling of the basis set, the latter cannot be satisfied in certain basis sets, and can give unrealistic results in others. The scaling procedure is applied to molecules at nonstationary points on the potential energy surface and it is found that energy components can change substantially, especially at short bondlengths, while the change in total energy is small. The effects on molecular properties are also small.