Abstract
We discuss a systematic construction of dimensionless quantum-mechanical equations. The process reduces the number of independent model parameters to a minimum and, at the same time, provides the natural units of length, energy, etc. in a clear, straightforward way. We compare this systematic procedure with the widely adopted one that consists of setting ℏ=1. As illustrative examples, we choose some simple one-dimensional models proposed recently for the study of localized states in inhomogeneous media.