Using Density Operators


The MCTDH programs can be used to describe a system using a density operator rather than a wavefunction. The program is used in exactly the same way as for wavefunctions, including the appropriate keyword (e.g. density2)in the RUN-SECTION of the input file. There are, however, some features which are not yet implemented for density operators. If an input file requests any of these features the programs stop and give appropriate error messages.

Furthermore, there are some features which affect only the density operator programs. They are described in the MCTDH input documentation, in the MCTDH output documentation, and in the MCTDH Hamiltonian/Liouvillian documentation together with the other features. A short list is given below.

Special input key words

Special operators


For the analysis of a density operator calculation some of the standard MCTDH analysis programs can be used, e.g. the autospec program or the overlap program. It is even possible to compute the overlap between type I andtype II density-operators. New analysis programs are listed together with the standard programs in the documentation of the analyse programs (see main menu).