Using the position as an independent variable, and time as the dependent variable, we derive the function $${\mathcal{P}}^{(\pm )}=\pm \sqrt{2m({\mathcal{H}}-{\mathcal{V}}(q))}$$, which generates the space evolution under the potential $${\mathcal{V}}(q)$$ and Hamiltonian $${\mathcal{H}}$$. No parametrization is used. Canonically conjugated variables are the time and minus the Hamiltonian ( $$-{\mathcal{H}}$$ ). While the classical dynamics do not change, the corresponding Quantum operator $${{{\hat{\mathcal P}}}}^{(\pm )}$$ naturally leads to a 1/2-fractional time evolution, consistent with a recent proposed space–time symmetric formalism of the Quantum (...) Mechanics. Using Dirac’s procedure, separation of variables is possible, and while the two-coupled position-independent Dirac equations depend on the 1/2-fractional derivative, the two-coupled time-independent Dirac equations lead to positive and negative shifts in the potential, proportional to the force. Both equations couple the (±) solutions of $${{{\hat{\mathcal P}}}}^{(\pm )}$$ and the kinetic energy $${\mathcal{K}}_{0}$$ (separation constant) is the coupling strength. Thus, we obtain a pair of coupled states for systems with finite forces, not necessarily stationary states. The potential shifts for the harmonic oscillator (HO) are $$\pm {\hbar {\omega}} /2$$, and the corresponding pair of states are coupled for $${\mathcal{K}}_{0}\ne 0$$. No time evolution is present for $${\mathcal{K}}_{0}=0$$, and the ground state with energy $${\hbar {\omega}} /2$$ is stable. For $${\mathcal{K}}_{0}>0$$, the ground state becomes coupled to the state with energy $$-{\hbar {\omega}} /2$$, and this coupling allows to describe higher excited states in the HO. Energy quantization of the HO leads to the quantization of $${\mathcal{K}}_{0}=k{\hbar {\omega}}$$ ( $$k=1,2,\ldots$$ ). For the one-dimensional Hydrogen atom, the potential shifts become imaginary and position-dependent. Decoupled case $${\mathcal{K}}_{0}=0$$ leads to plane-waves-like solutions at the threshold. Above the threshold ( $${\mathcal{K}}_{0}>0$$ ), we obtain a plane-wave-like solution, and for the bounded states ( $${\mathcal{K}}_{0}<0$$ ), the wave-function becomes similar to the exact solutions but squeezed closer to the nucleus. (shrink)