Links:
HOME
Who am I?
Useful databases
CCL resources



contacts: tim_mail (AT) ukr (DOT) net

Computational Chemistry Software


News

  • (15.12.2013): Cygwin version of antechamber-1.27 binaries is now available
  • (14.12.2013): Cygwin version of GROMACS-4.6.5 binaries is now available
    The compilation procedure is outlined here
    Note: if you have no MPI installed, -nt 1 key may be useful!

  • (18.10.2012): An updated version of EGView is avalable: now ORCA output files (for geometries and energies) are suported
  • (25.08.2012): NwChem 6.1.1 binaries build with openmpi-1.4.5 for 32-bit LINUX are available (64-bit mpirun is included; 32-bit mpirun is here; please, mail to me and say, whether it works ok :) )
  • (08.05.2012): The NwChem Feature (but not a 'bug', IMHO):
    * the Dunning basis sets were designed to be used with spherical basis functions.
      The NWChem default is cartesian, so the basis section input needs to iclude spherical keyword
      ("basis spherical" instead of "basis")
    * the "freeze atomic" option might be needed to be added in MP2 calculations, since
       (1) this is the default in Gaussian and noobs will be confused when
           all-electron result does not agree with Gaussian, and
       (2) Dunning basis sets are supposed to be used with frozen-core for correlated calculations.
    
    See also the discussion on the topic:
     * HF SCF energies: One can get consistent results from both programs by either specifying
       "basis cartesian" instead of "basis spherical" the NWChem input or specify 5D functions
       in the Gaussian03 input.
     * In Gaussian, specifying MP2 defaults to freezing the core orbitals, while in NWChem, MP2
       signifies full correlation. In order to get the same energies: specify "MP2(full)/6-31G*"
       in the Gaussian03 input or specify "freeze atomic" in the MP2 directive of an NWChem input.
    
  • (08.03.2012) New version of nwRun, a user-friendly GUI shell for running nwchem.exe is now available (see description here)
  • (08.03.2012) Be sure to use NWCHEM_BASIS_LIBRARY environment variable to specify the path to NwChem basis set description files
  • (08.03.2012) The nw-6.1-basis_library.zip arvhieve contains basis set collection from NwChem 6.1
  • (04.02.2012) NwChem 6.1 for Windows in now available (the simplest classical build - see note.txt in arcieve; 19 Mb)
    More builds (including python, mpi, wfn generator etc) are coming soon...
  • (02.02.2012) NWChem developers announced that NWChem 6.1 has been released.

NWChem 6.0 for Windows

Download cygwin-based win32 binaries, built from original NwChem 6.0 source code with minor modifications to achieve successful compilation:

The user manual documentation is also avaiballe in single-file pdf format.

A GUI user-friendly shell for running nwchem.exe is also available (see description here)

Updated 01.10.2011
For technical support and/or any questions please, write to tim_mail (at) ukr (dot) net


EGView (version 09.07.2011)

A convenient tool to analyze results of Gaussian 03/09 BSSE-corrected calculations
Features:
  • Freeware!
  • Compatible with Gaussian 03 and Gaussian 09
  • Reports bsse-corrected Stabilization energy in kcal/mole
  • Able to read .out files from .zip archives
Download

How does it work?

BSSE-corrected Stabilization energy SE is obtained as
SE = EA+BDCBS - EADCBS - EBDCBS = EA+BCP - EAMCBS - EBMCBS
where EA+BDCBS is BSSE-uncorrected electron energy, EADCBS is the electron energy of fragment A in a complex obtained using DCBS (Dimer-Centered Basis Set), EBDCBS is the electron energy of fragment B in a complex obtained using DCBS (Dimer-Centered Basis Set), EA+BCP is BSSE-corrected electron energy using counterpoise method:
EA+BCP = EA+BDCBS + ΔEBSSE with the BSSE-correction value ΔEBSSE = EAMCBS - EADCBS + EBMCBS - EBDCBS
Note that ΔEBSSE > 0 sicnce EXDCBS < EXMCBS.

All the values from these equations appear in the Gaussian .out file if the counterpoise keyword is used.
Here are Gaussian keywords identifying different stages of the counterpoise procedure as they appear in Gaussian .out file:
EADCBS

 Counterpoise: doing DCBS calculation for fragment   1 NewBq=T
 ...
 SCF Done:  E(RB+HF-LYP) =  -56.5595347922     A.U. after    5 cycles
             Convg  =    0.1804D-08             -V/T =  2.0095
             S**2   =   0.0000 
Here NewBq is a synonym for NewGhost
and DCBS = Dimer centered basis set
EBDCBS
 Counterpoise: doing DCBS calculation for fragment   2 NewBq=T 
 ...
 SCF Done:  E(RB+HF-LYP) =  -114.503484307     A.U. after    6 cycles
             Convg  =    0.3794D-08             -V/T =  2.0090
             S**2   =   0.0000 
EAMCBS
 Counterpoise: doing MCBS calculation for fragment   1 
 ...
 SCF Done:  E(RB+HF-LYP) =  -56.5577674045     A.U. after    5 cycles
             Convg  =    0.2728D-08             -V/T =  2.0092
             S**2   =   0.0000 
Here MCBS = monomer-centered basis set
EBMCBS
 Counterpoise: doing MCBS calculation for fragment   2 
 ...
 SCF Done:  E(RB+HF-LYP) =  -114.503149487     A.U. after    5 cycles
             Convg  =    0.9897D-08             -V/T =  2.0090
             S**2   =   0.0000 
For post-SCF methods keywords such as EUMP2 etc appears after "Counterpoise: doing XXXX calculation for fragment Y"
The following output appears regardless of the energy calculation method used:
EA+BCP
 Counterpoise: corrected energy =    -171.065201221288
and the BSSE-correction energy (ΔEBSSE)
 Counterpoise: BSSE energy =       0.002102207582 

Note that all these values are calculated for fragments geometries as they are in complex, so their deformation energy is not included. This is a good approximation (< 0.1 kcal/mole) only if interacting molecules are rigid enough.
See also the sample calculation

Some open-source QC code references

The quantum-chemistry freeware libraries
Name link brief description
libint http://sourceforge.net/p/libint efficient computation of quantum mechanical matrix elements over Gaussian basis sets
used in: MPQC, ORCA, Psi, CP2K packages
libxc http://www.tddft.org/programs/octopus/wiki/index.php/Libxc a library of exchange-correlation functionals for density-functional theory
used in: Abinit, APE, AtomPAW, Atomistix ToolKit BigDFT, DP (linear response TDDFT code), ERKALE, GPAW, Elk, exciting, octopus(real-space (TD)DFT code), Yambo.
libderiv http://www.psicode.org/doc/libs/doxygen/html/group__DERIV.html computes first and second derivatives of ERIs (electron repulsion integrals) with respect to the coordinates of the basis function origin
used in: Psi.

Updated: Aug 23, 2011


Leave a comment/question/suggestion