Hypervirial and Hellmann-Feynman Theorems Applied to Anharmonic Oscillators
- 15 August 1972
- journal article
- Published by AIP Publishing in The Journal of Chemical Physics
- Vol. 57 (4) , 1734-1737
- https://doi.org/10.1063/1.1678462
Abstract
A set of hypervirial theorems plus the Hellman-Feynman theorem are applied to a general anharmonic oscillator. The exact energy and expection values of powers of the position coordinate are expanded in a power series of the anharmonic coupling constant and it is shown that use of the above theorems enables one to express each term in these expansions solely in terms of the unperturbed energy and known constants. This procedure thus eliminates the usual tedious calculations of sums over intermediate states of products of matrix elements which arise in nth order Rayleigh-Schrödinger perturbation theory.Keywords
This publication has 11 references indexed in Scilit:
- A note on quantum-mechanical sum rulesPhysics Letters A, 1969
- Studies of off-diagonal hypervirial constraintsTheoretical Chemistry Accounts, 1969
- Off-Diagonal Hypervirial Theorems as ConstraintsThe Journal of Chemical Physics, 1968
- Operator equations in perturbation theoryProceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, 1967
- Determination of Hypervirial Operators in Perturbation TheoryThe Journal of Chemical Physics, 1967
- Use of Hellmann—Feynman and Hypervirial Theorems to Obtain Anharmonic Vibration—Rotation Expectation Values and Their Application to Gas DiffractionThe Journal of Chemical Physics, 1966
- Hypervirial Functions and the Positive Powers of the Radial Coordinate Operator in He and H—The Journal of Chemical Physics, 1965
- Hypervirial theorems and perturbation theory in quantum mechanicsProceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, 1965
- Some Applications of Hypervirial Theorems to the Calculation of Average ValuesAmerican Journal of Physics, 1962
- Classical and Quantum Mechanical Hypervirial TheoremsThe Journal of Chemical Physics, 1960