The Perl Toolchain Summit needs more sponsors. If your company depends on Perl, please support this very important event.

NAME

Chemistry::ESPT::Gfchk - Gaussian formatted checkpoint file object.

SYNOPSIS

   use Chemistry::ESPT::Gfchk;

   my $fchk = Chemistry::ESPT::Gfchk->new();

DESCRIPTION

This module provides methods to quickly access data contained in a Gaussian formatted checkpoint file. Guassian formatted checkpoint files can only be read currently.

ATTRIBUTES

All attributes are currently read-only and get populated by reading the assigned ESS file. Attribute values are accessible through the $Gfchk->get() method.

C

NBASIS x NBASIS coefficient matrix. The coefficients correspond to Alpha or Beta depending upon what spin was passesd to $Gfchk->analyze().

CARTCOORD

NATOMS x 3 matrix containing the current Cartesian coordinates

EELEC

Electronic energy for the theroy level employed.

ESCF

SCF energy. This will be either the Hartree-Fock or the DFT energy. See Gaussian documentation for more information.

EIGEN

Array with length NBASIS, containing the eigenvalues. The eigenvalues correspond to Alpha or Beta depending upon what spin was passesd to $Gfchk->analyze().

FUNCTIONAL

String containing the DFT functional utlized in this job.

GRADIENT

Array containing the Cartesian gradients.

HESSIAN

Lower-triangular matrix containing the Cartesian Hessian.

HOMO

Number corresponding to the highest occupied molecular orbital. The value corresponds to either Alpha or Beta electrons depending upon what spin was passesd to $Gfchk->analyze().

IRCCOORD

A rank three tensor containing Cartesian coordinates for each IRC geometry.

IRCENERGY

Array, with length IRCPOINTS, containing the electronic energy at each IRC geometry.

IRCGRADIENT

Cartesian gradients for each IRC geometry stored as a rank two tensor.

IRCPOINTS

Total number of IRC steps.

IRCSTEP

Array of reaction coordinate values for each IRC step.

KEYWORDS

Array containing Gaussian keywords used in this job.

MASS

Array with length NATOMS, containing the atomic masses.

NREDINT

Total number of redundant internal coordinates.

REDINTANGLE

Number of redundant internal angles.

REDINTBOND

Number of redundant internal bonds.

REDINTCOORD

NREDINT x 4 matrix containing the redundant internal coordinates. Each coordinate is defined by four integers corresponding to the atom numbers. Bond coordinates have zeros in columns 3 & 4. Bond angle coordinates have a zero in column 4.

REDINTDIHEDRAL

Number of redundant internal dihedrals.

REDINTGRADIENT

Array containing the redundant internal gradient.

REDINTHESSIAN

Lower-triangular matrix containing the redundant internal Hessian.

ROUTE

Gaussian route line

SSQUARED

<S**2> expectation value.

METHODS

Method parameters denoted in [] are optional.

$fchk->new()

Creates a new Gfchk object

$fchk->analyze(filename [spin])

Analyze the spin results in file called filename. Spin defaults to Alpha.

VERSION

0.03

SEE ALSO

Chemistry::ESPT::ESSfile, Chemistry::ESPT::Glib, http://www.gaussian.com

AUTHOR

Dr. Jason L. Sonnenberg, <sonnenberg.11@osu.edu>

COPYRIGHT AND LICENSE

Copyright 2008 by Dr. Jason L. Sonnenberg

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself. I would like to hear of any suggestions for improvement.