How do I get the two circles to be on the same height? I tried the following
\newcommand{\sss}{\;\;\;\;\;\;\:}
\overset{\circ}{R}_{\mu\nu\sigma\lambda}\overset{\circ\sss}{R^{\mu\nu\sigma\lambda}}
\overset{\circ}{R}_{\mu\nu\sigma\lambda}\overset{\circ}{R}^{\mu\nu\sigma\lambda}
Any suggestions?