Program BO-VIR Version 1.01
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I. Mayer
Chemical Research Center, Hungarian Academy of Sciences
H-1515 Budapest, P.O.Box 17, Hungary
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This program is a special large dimensions version of the programs by
I. Mayer and A. Hamza performing *a posteriori* analysis of the single
determinant Hartree-Fock ab initio wave wave functions produced by the
widely used "Gaussian" system G92, G94, G98, G03.
This version performs
A.) BOND ORDER and VALENCE analysis (I. Mayer, Chem. Phys. Lett. 97, 270
1983; addendum for open shells: Chem. Phys. Lett. 117, 396, 1985, etc.);
and
B.) ENERGY DECOMPOSITION analysis into one- and di-atomic energy
components based on the VIRIAL THEOREM. Thus the sum of energy components
recovers the total single determinant molecular energy as accurately as
accurately the virial theorem is satisfied.
ATTENTION! ATTENTION! ATTENTION! ATTENTION!
! The energy decomposition based on the virial theorem may be used only
! is ithe STACIONARY POINTS (minima, saddle points) on the potential energy
! surface!!! (In the framework of the Born-Oppenheimer separation, the virial
! theorem in its usual form is satisfied only in the staionary points.)
This program is applicable up to 2000 basis orbitals. It is easily
be extended further, by increasing all the "parameters" which are = 2000
to some larger value. The parameters set =10000 should be increased
proportionally.
For other programs of the suite, also with other energy partitioning
schemes and "fyzzy atoms" analysis see the web-site
http://occam.chemres.hu/programs
This program uses routines from the program APOST by I. Mayer and
A. Hamza - see the web-site indicated.
The basic bond order routine used here was written in 1982/83 by I. Mayer.
The virial theorem analysis is based on the simple expression of
the total kinetic energy T as sum of one- and two-center components.
(In the points where the virial theorem is fulfilled the total
energy E equals to E = - T.)
This type of analysis based on the virial theorem was proposed - in
a somewhat different context - by E. Kapuy and C. Kozmutza (Budapest,
Hungary) back in the late 1970-s [R. Daudel, E. Kapuy, C. Kozmutza,
M.E. Stephens, Theor. Chim. Acta 53, 147 (1979); also see C. Kozmutza
and E. Tfirts, Int. J. Quant. Chem. 104, 578 (2005)].
Installation of the program:
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The "tar" file contains all the necessary FORTRAN source files as well
as a "Makefile", which should be appropriate to produce the executable
by issuing the command "make" on a UNIX or Linux system. (If necessary,
replace the call to "f77" in the Makefile by the name of your FORTRAN
compiler.) The name of the executable generated is "virial".
Usage of the program:
The only input required by the program is the "formatted checkpoint
file" (Test.FChk) which is produced by the Gaussian, provided that the
FormCheck keyword is included in the Gaussian input. In the program
the file Test.FChk is used for input as the FORTRAN file fort.14,
and is copied to file "Tmp" for actual processing (file fort.15).
An alternative is to conserve the binary checkpoint file which is
produced during the Gaussian run (include %chk="filename" in the input)
and to format it by using the command "formchk" which is a part of the
Gaussian system. The formatted checkpoint file should then be renamed
(copied) to Test.Fchk (or to fort.14, if the statement
"open(14,file='Test.FChk')" has been deleted from "subroutine input".
A convenient way of using the program is to include it in the
script performing the Gaussian run; one should take care of ensuring
that "BO-VIR" should NOT start before Gaussian is finished. It is
desirable to delete or rename the formatted checkpoint file Test.FChk
after the calculation, in order to avoid its unwanted reuse.
Cite this program as:
I. Mayer, Program "BO-VIR", Version 1.0
(Chemical Research Center, Hungarian Academy of Sciences),
Budapest, 2005.
Limitations:
This version of the program is applicable up to 100 atoms,
2000 basis orbitals and 10000 primitive Gaussians
These numbers can easily be extended further by increasing
every parameter, which is equal 100, 101, 2000 or 10000.
(Parameter maxat1 should be set equal "the value of maxat"+1.)
Bugs etc.
Please report bugs, problems etc. to the e-mail address above
above - we will try our best to help you.