Chapront-Touze & Chapront (1983, 1988) and Chapront-Touze & Francou (2003) provide precise semi-analytic models for the Moon vs the geocenter, which match DE405 at the few meters level. While computationally costly, consisting of around 35,000 harmonic terms, we can provide an implementation. And, the series can be truncated early to obtain less precise results faster if needed.

• The initial implementation truncates the series at the 1 mas / 1 m level, resulting in a maximal accuracy at the few tenths of an arcsec or 100s of meters level.