Documentation

Please Cite This Work

You are welcomed to use DMRG++ and publish data obtained with it. If you do, please cite this work.

DMRG++ Tutorial Materials

Mon, 15 Aug 2016 13:00:00 EDT Slides and inputs for the DMRG 101 Introduction to Theory and Practice tutorial have been posted to the below URL. Thanks to all who attended!

Mailing list for DMRG++ and Auxiliary Codes

Thu, 4 Aug 2016 13:00:00 EDT To view the messages sent to the list please visit the link below and click on dmrgpp Archives, and from there click on the Thread for the month you are interested in. To post to the list, please write an email to dmrgpp (at) ornl.gov Message to the list are worldwide viewable.

DMRG 101 Tutorial

Thu, 28 Jul 2016 11:00:00 EDT Title: Density Matrix Renormalization Group 101: Introduction to Theory and Practice
When: Fri, Aug 12, 2016
Where: Oak Ridge National Laboratory, Oak Ridge, TN, USA
There is no cost but registration is required. Here is the official announcement and agenda.

DMRG++ Parallel Compilation

Mon, 1 Feb 2016 11:09:35 EDT Faster compilation can now be achieved if your computer has multiple cores. First recompile PsimagLite cd PsimagLite/ cd drivers/ perl make.pl cd ../lib perl configure.pl make Now DMRG++ cd ../../dmrgpp/src perl configure.pl make -j 16 where the example uses 16 cores. Use more or less cores depending on your hardware. IMPORTANT: After each git pull please run perl configure.pl in both PsimagLite/lib and dmrgpp/src

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++.