  A document has recently been posted on the arXiv [1], describing analytical
formulas and results of particle tracking simulations, for precision tests of
numerical integration algorithms for an EDM (electric dipole moment) storage
ring. In the context of an all-electric storage ring, the authors cite
theoretical formulas by Orlov [2]. However, the reference to Orlov is to a talk
at a workshop in 2012, and is unpublished and difficult for independent
researchers to access and validate. This note rederives and generalizes some of
Orlov's principal results, using a Hamiltonian formalism, and also corrects
some details in both Orlov's note [2] and the arXiv post [1].
