Digital object identifier added of the code release paper.
DOI link corrected
Reshuffled some of the DMRG-SCF functions and variables.
Resummed the Coulomb and exchange interaction of the occupied and active electrons.
Separated DMRG and Hessian matrix elements construction.
Cut corners at two-body rotation.

The calculation of the gradient and the Hessian require two-body matrix elements with at most 2 virtual indices. This allows to reduce the computational time required for the blockwise transformation of the two-body matrix elements based on the flag "cutCorners".