%0 Journal Article %T Natural Extension of the Schrödinger Equation to Quasi-Relativistic Speeds %A Luis Grave de Peralta %J Journal of Modern Physics %P 196-213 %@ 2153-120X %D 2020 %I Scientific Research Publishing %R 10.4236/jmp.2020.112012 %X A Schrödinger-like equation for a single free quantum particle is presented. It is argued that this equation can be considered a natural relativistic extension of the Schrödinger equation for energies smaller than the energy associated to the particle¡¯s mass. Some basic properties of this equation: Galilean invariance, probability density, and relation to the Klein-Gordon equation are discussed. The scholastic value of the proposed Grave de Peralta equation is illustrated by finding precise quasi-relativistic solutions for the infinite rectangular well and the quantum rotor problems. Consequences of the non-linearity of the proposed equation for the quantum superposition principle are discussed. %K Quantum Mechanics %K Schrö %K dinger Equation %K Klein-Gordon Equation %K Relativistic Quantum Mechanics %U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=98147