The latest version of MRCC is released on September 7, 2015.
The important new features and changes are as follows.
1) Implementation of effective core potentials (ECPs). Numerous ECPs and the corresponding basis sets have been included.
2) Implementation of the dRPA75 approach.
3) Implementation of intrinsic atomic orbitals (IAOs) and intrinsic bond orbitals (IBOs) of Knizia.
4) The direct random-phase approximation (dRPA) correlation energy can now be calculated using the plasmon formula also with unrestricted orbitals.
5) Improved restarting for SCF.
6) A couple of bugs have been fixed and the manual has been improved.
It is recommended for every user to upgrade to this version.