Documentation

Compiling and running

After downloading you can compile DMRG++ code with:

$ cd PsimagLite/lib
$ perl configure.pl
 (You may now edit Config.make)
$ make
$ cd ../../dmrgpp/src
$ perl configure.pl
 (You may now edit Config.make)
$ make

and run it with

$ cp ../TestSuite/inputs/input2.inp .
$ ./dmrg -f ../TestSuite/inputs/input2.inp

After it finishes, data will be saved in data2.txt. You can run

grep Energy data2.txt

to obtain the energies for all steps of the algorithm.

Obtaining Static Observables

Observables can be obtained post-processing by compiling and running the observer code:

$ make observe
$ ./observe -f input2.inp cc

The output will be a n times n/2 matrix for <c⁺_i c_j> in i, and j. Other possibilities include nn for <n_i n_j> correlations, and szsz for spin-z correlations.

Where to find more documentation

There's plenty of documentation for DMRG++.

DMRG 101: Introduction to Theory and Practice, Aug. 12, 2016. Oak Ridge, TN, USA.
DMRG++ Tutorial by N. Patel
The introducing paper arXiv:0902.3185 published in Computer Physics Communications 180 (2009) 1572-1578. Some things are out-of-date but the overall structure and philosophy of the code is the same.
The DMRG++ manual. This is incomplete but it will be updated as there's interest.
The implmentation of the SU(2) symmetry in DMRG++ is described in arXiv:1003.1919
This March Meeting 2010 talk has a focus on SU(2) symmetries but describes other parts of the implementation as well.
Further info is given on parts of this talk I gave at Sandia National Laboratories on Oct. 2010.
There is also this paper on time evolution using DMRG++.