Experimental Test for Absence of R-Term in Schroedinger Equation in   Curved Space
  We point out that the presence of a term proportional to the scalar curvature in the Schroedinger equation in curved space can easily be detected in atomic spectra with Russel-Saunders coupling by a violation of the Lande interval rule for adjacent levels E_J-E_{J-1} propto J. 
H. Kleinert