Provided by: chemps2_1.6-3_amd64 
NAME
chemps2 - spin-adapted DMRG for ab initio quantum chemistry
SYNOPSIS
chemps2 [OPTION] ...
DESCRIPTION
chemps2 is a scientific code to perform spin-adapted density matrix renormalization group (DMRG)
calculations for ab initio quantum chemistry fcidump files. This method allows one to obtain numerical
accuracy in active spaces beyond the capabilities of full configuration interaction (FCI) and can return
the active space 2-RDM. The method is therefore ideal to replace the FCI solver in the complete active
space configuration interaction (CASCI) and complete active space self consistent field (CASSCF) methods.
The link to the user manual can be found in the section SEE ALSO.
OPTIONS
SYMMETRY
Conventions for the symmetry group and irrep numbers (same as psi4):
| 0 1 2 3 4 5 6 7
---------|-----------------------------------------
0 : c1 | A
1 : ci | Ag Au
2 : c2 | A B
3 : cs | Ap App
4 : d2 | A B1 B2 B3
5 : c2v | A1 A2 B1 B2
6 : c2h | Ag Bg Au Bu
7 : d2h | Ag B1g B2g B3g Au B1u B2u B3u
ARGUMENTS
-f, --fcidump=filename
Set the fcidump filename. Note that orbital irreps in this file follow molpro convention!
-g, --group=int
Set the psi4 symmetry group number [0-7] which corresponds to the fcidump file.
-m, --multiplicity=int
Overwrite the spin multiplicity [2S+1] of the fcidump file.
-n, --nelectrons=int
Overwrite the number of electrons of the fcidump file.
-i, --irrep=int
Overwrite the target wavefunction irrep [0-7] of the fcidump file (psi4 convention).
-D, --sweep_d=int,int,int
Set the bond dimensions for the successive sweep instructions (positive integers).
-E, --sweep_econv=flt,flt,flt
Set the energy convergence to stop sweep instructions (positive floats).
-M, --sweep_maxit=int,int,int
Set the maximum number of sweeps for the sweep instructions (positive integers).
-N, --sweep_noise=flt,flt,flt
Set the noise prefactors for the successive sweep instructions (floats).
-e, --excitation=int
Set which excitation should be calculated (positive integer). If not set, the ground state is
calculated.
-o, --twodmfile=filename
Set the filename to dump the 2-RDM. If not set, the 2-RDM is not dumped.
-c, --checkpoint
Read and create MPS checkpoints.
-p, --print_corr
Print correlation functions.
-t, --tmpfolder=path
Overwrite the tmp folder for the renormalized operators (default /tmp).
-r, --reorder=int,int,int
Specify an orbital reordering w.r.t. the fcidump file (counting starts at 0).
-h, --help
Display this help.
EXAMPLE
$ cd /tmp
$ wget 'https://github.com/SebWouters/CheMPS2/raw/master/tests/matrixelements/H2O.631G.FCIDUMP'
$ ls -al H2O.631G.FCIDUMP
$ chemps2 --fcidump=H2O.631G.FCIDUMP \
--group=5 \
--sweep_d=200,1000 \
--sweep_econv=1e-8,1e-8 \
--sweep_maxit=2,10 \
--sweep_noise=0.05,0.0 \
--twodmfile=2dm.out \
--print_corr \
--reorder=6,5,4,3,2,1,0,7,8,9,10,11,12
AUTHOR
Written by Sebastian Wouters <sebastianwouters@gmail.com>
BUGS
Reporting bugs: https://github.com/sebwouters/CheMPS2/issues
SEE ALSO
User manual: http://sebwouters.github.io/CheMPS2/index.html
COPYRIGHT
CheMPS2: a spin-adapted implementation of DMRG for ab initio quantum chemistry
Copyright (C) 2013-2015 Sebastian Wouters
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.