Accession Number:

AD0626936

Title:

APPLICATION OF THE HELLMANN-FEYNMAN AND VIRIAL THEOREMS TO THE THEORETICAL CALCULATION OF MOLECULAR POTENTIAL CONSTANTS,

Descriptive Note:

Corporate Author:

UPPSALA UNIV (SWEDEN) QUANTUM CHEMISTRY GROUP

Personal Author(s):

• Schwendeman,Richard

Report Date:

1965-06-01

Pagination or Media Count:

28.0

Abstract:

The Hellmann-Feynman theorem is discussed with emphasis on the importance of the choice of integration variables to the appearance of the equations, the stability of the wave functions, and the reliability of calculations. The Hellman-Feynman expression for the z-component of the force on a single nucleus is differentiated successively to obtain expressions which are related to the harmonic and anharmonic potential constants in a molecule. The method used to simplify the differentiations is also used to derive two expressions for the field gradient part of the nuclear quadrupole coupling constant the two expressions involve only convergent integrals. The virial-theorem expression for diatomic molecules is differentiated to obtain equations for the cubic and quartic potential constants and for the Dunham constants. Application of the equations to quantumchemical calculation of the potential constants is discussed. Author

Descriptors:

• *MOLECULAR ENERGY LEVELS
• WAVE FUNCTIONS
• STABILITY
• QUANTUM THEORY
• MOLECULAR PROPERTIES
• POTENTIAL ENERGY
• FIELD THEORY
• MATRICES(MATHEMATICS)

Subject Categories:

• Atomic and Molecular Physics and Spectroscopy
• Quantum Theory and Relativity

Distribution Statement:

APPROVED FOR PUBLIC RELEASE