Generalization of the Thomson formula for general harmonic functions

The paper continues the investigation of electron and ion optical properties of electric and magnetic fields which can be represented in an analytical form. The target of this research is new recipes for generating analytical solutions of 3D Laplace equation, in particular, for generating 3D harmonic functions which are homogeneous in Euler terms. Linear algebraic expressions with first order partial derivatives which generalize the widely known Thomson formula (Kelvin transformation), are analyzed. The paper provides an exhaustive list of symmetric and homogeneous first order differentiating expressions that convert an arbitrary 3D harmonic function into some new 3D harmonic functions. The produced 3D expressions are generalized for the n-dimensional case.