ABSTRACT
We study the interaction of an atomic system with an electromagnetic radiation field. The Schrödinger equation for a mass point of charge q in an electromagnetic field described by a vector potential A is () i h ∂ ψ ∂ t = [ − ħ 2 2 m ∇ 2 + i q ħ m c A · ∇ + V ] ψ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429493645/749bab20-4a79-4f5a-8c66-d9e9a36a87b9/content/eq876.tif"/>
