Comment on "Prospect of optical frequency standard based on a 43Ca+ ion"

Abstract

A recent evaluation of the frequency uncertainty expected for an optical frequency standard based on a single trapped $^{43}$Ca$^+$ ion was published in Phys. Rev. A {\bf 72} (2005) 043404. The paper contains some interesting information like systematic frequency shifts but fails to depict their uncertainty, leading to confuse accuracy and precision. The conclusions about the major contribution to the frequency shift are not consistent with the presented calculations and omit comparisons with data published previously.