It is also possible to use geminals with different exponents for core-core and core-valence calculation [see Mol. Phys. 109, 407 (2011)] In this case the exponents are specified as
The smallest value is used for valence correlation, the second-smallest for core-valence and the largest for core-core pairs. If only 2 values are given, core-core and core-valence pairs are treated with the same exponent. Note that the core directive is usually needed to include correlation of inner-shell orbitals.
In addition, also linear R12-methods () are available (DF-MP2-R12 and DF-LMP2-R12). However, these are no longer recommended since the non-linear correlation factor yields much better accuracy, numerical stability and convergence with respect to the AO, DF and RI basis sets.