Return to Answer

The Löwdin method to obtain lower bounds to energy eigenvalues of the Schrödinger equation has been reviewed in Lower Bounds to Energy Eigenvalues (1976). It has been applied to the quartic potential in Upper and Lower Bounds to the Eigenvalues of Double-Minimum Potentials (1965). See table I, where the coefficient $a$ is given by $a^2=-v_2 v_4^{-2/3}$ and then the lower bound is $E v_4^{-1/3}$ with $E$ the "level 0 energy" from table I.

The Löwdin method to obtain lower bounds to energy eigenvalues of the Schrödinger equation has been reviewed in Lower Bounds to Energy Eigenvalues (1976). It has been applied to the quartic potential in Upper and Lower Bounds to the Eigenvalues of Double-Minimum Potentials (1965). See table I, where the coefficient $a$ is given by $a^2=-v_2 v_4^{-2/3}$ and then the lower bound is $\frac{1}{2}E v_4^{-1/3}$ with $E$ the "level 0 energy" from table I. For example, for $a=2.6375$ I find $E_0\geq-8.53234$, well above $-a^4/4=-12.0981$.

The Löwdin method to obtain lower bounds to energy eigenvalues of the Schrödinger equation has been reviewed in Lower Bounds to Energy Eigenvalues (1976). It has been applied to the quartic potential in Upper and Lower Bounds to the Eigenvalues of Double-Minimum Potentials (1965). See table I, where the coefficient $a$ is given by $a^2=-v_2 v_4^{-2/3}$ and then the lower bound is $E v_4^{-1/3}$ from table I.

The Löwdin method to obtain lower bounds to energy eigenvalues of the Schrödinger equation has been reviewed in Lower Bounds to Energy Eigenvalues (1976). It has been applied to the quartic potential in Upper and Lower Bounds to the Eigenvalues of Double-Minimum Potentials (1965). See table I, where the coefficient $a$ is given by $a^2=-v_2 v_4^{-2/3}$ and then the lower bound is $E v_4^{-1/3}$ with $E$ the "level 0 energy" from table I.

The Löwdin method to obtain lower bounds to energy eigenvalues of the Schrödinger equation has been reviewed in Lower Bounds to Energy Eigenvalues (1976). It has been applied to the quartic potential in Upper and Lower Bounds to the Eigenvalues of Double-Minimum Potentials (1965). See table I, where $v_2$ and $v_4$ are the $x^2$ and $x^4$ coefficients of the potential.

The Löwdin method to obtain lower bounds to energy eigenvalues of the Schrödinger equation has been reviewed in Lower Bounds to Energy Eigenvalues (1976). It has been applied to the quartic potential in Upper and Lower Bounds to the Eigenvalues of Double-Minimum Potentials (1965). See table I, where the coefficient $a$ is given by $a^2=-v_2 v_4^{-2/3}$ and then the lower bound is $E v_4^{-1/3}$ from table I.