AKIRA

Author

Johannes Neugebauer, Carmen Herrmann and Markus Reiher.

Origin

Jena University, Germany.

Version

AKIRA 3.0.0

Official Web Site

http://www.ipc.uni-jena.de/reiher/download_akira.html

Brief Program Description

AKIRA is a program that can perform mode tracking of molecular vibrations, where only calculations for the normal modes are performed, thus this avoids the calculation of the full Hessian matrix. This method is very useful since for most chemical systems; only the normal modes are of interest. The mode tracking method is particularly useful for very large molecules where the complete calculation of the spectrum is not feasible. It is also useful if only limited computing time is available as well as for smaller systems with very accurate high level ab initio calculations.

Since vibrational frequencies and normal modes calculation require the eigenvalues and eigenvectors of the Hessian matrix when the electronic energy gradient is zero, therefore geometry optimisation must be performed first.

Areas of Application

AKIRA requires single point calculations with either DALTON, TURBOMOLE, ADF or Gaussian. AKIRA does not directly interact with any of these software packages, it only scans the output of them in order to extract all the relevant raw data for the mode tracking protocol.

A tool called akiradefine is available to allow the easy set up and handling of the input file required for the mode tracking calculations. Once the input file has been set up using akiradefine the calculation can then be run using the command runakira.

Normal modes may be tracked for any electronic structure method implemented in TURBOMOLE, ADF, or Gaussian for which analytic energy gradients are available.

The most important step in setting up the input file via akiradefine is to select the initial basis vectors within the pint menu. This allows users to select which particular modes to be tracked such as stretching, bending, torsional, out-of-plane, etc. Prior to the use of akiradefine, depending on the software package chosen for the single point energy calculations, it is necessary to prepare the input files of these in a specific way.

Implementation and Access

AKIRA can be accessed on Magellan by the command:

$CHEM/runakira

The interactive script akiradefine can be accessed on Magellan by the command:

$CHEM/runakira define

Please refer to the man page for details.

Machines

Available on Magellan.

Documentation

A Unix-style man page is available online, gives a summary of the implementation and the options available for the program, accessible by typing: man runakira.The user manual is available for download from the AKIRA web site.

Literature References

Please refer to the AKIRA web site for details.

Specialist Support

Dr Helen Tsui. Address: Department of Chemistry, Imperial College London, South Kensington, London SW7 2AZ. Tel: 020 7594 1220 Email: helen.tsui@imperial.ac.uk.

Program Restrictions and Comments

N/A