OnWorks favicon

chemps2 - Online in the Cloud

Run chemps2 in OnWorks free hosting provider over Ubuntu Online, Fedora Online, Windows online emulator or MAC OS online emulator

This is the command chemps2 that can be run in the OnWorks free hosting provider using one of our multiple free online workstations such as Ubuntu Online, Fedora Online, Windows online emulator or MAC OS online emulator



chemps2 - spin-adapted DMRG for ab initio quantum chemistry


chemps2 [OPTION] ...


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.


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

-f, --fcidump=filename
Set the fcidump filename. Note that orbital irreps in this file follow molpro

-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

-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.

$ 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 \

Use chemps2 online using onworks.net services

Free Servers & Workstations

Download Windows & Linux apps

  • 1
    Laravel is a free, open-source PHP web
    framework. Features:Expressive,
    beautiful syntax.Database agnostic
    migrationsSchema builderPainless
    routingPowerful queu...
    Download Laravel
  • 2
    nmon for Linux
    nmon for Linux
    nmon is short for Nigel's
    Performance Monitor It either shows you
    the stats on-screen updating once a
    second or saves the data to a CSV file
    for later anal...
    Download nmon for Linux
  • 3
    VBA-M (Archived - Now on Github)
    VBA-M (Archived - Now on Github)
    Project has moved to
    Features:Cheat creationsave statesmulti
    system, supports gba, gbc, gb, sgb,
    Download VBA-M (Archived - Now on Github)
  • 4
    Linux System Optimizer and Monitoring
    Github Repository:
    Audience: End Users/Desktop. User
    interface: Qt. Programming La...
    Download Stacer
  • 5
    Fork of TeamWinRecoveryProject(TWRP)
    with many additional functions, redesign
    and more Features:Supports Treble and
    non-Treble ROMsUp-to-date Oreo kernel,
    Download OrangeFox
  • 6
    itop - ITSM  CMDB OpenSource
    itop - ITSM CMDB OpenSource
    IT Operations Portal: a complete open
    source, ITIL, web based service
    management tool including a fully
    customizable CMDB, a helpdesk system and
    a document man...
    Download itop - ITSM CMDB OpenSource
  • 7
    Clementine is a multi-platform music
    player and library organizer inspired by
    Amarok 1.4. It has a fast and
    easy-to-use interface, and allows you to
    search and ...
    Download Clementine
  • More »

Linux commands