VEDA

Vibrational Energy Distribution Analysis (VEDA)

VEDA 4 (Windows)

VEDA 4xx (Windows) Veda version for up to 480 atoms.

 author: Michał H. Jamróz, Warsaw

 Once results of the VEDA analysis are to be published, The reference should be cited as follows:

Michal. H. Jamróz, Vibrational Energy Distribution Analysis VEDA 4, Warsaw, 2004-2010

The VEDA computer program is optimizing the set of internal coordinates for elucidation of IR and Raman experimental/theoretical spectra. As a result, the theoretical normal modes are represented by internal coordinates giving users a more intuitive view of the molecular movements. Each of the internal coordinates is expressed as a superposition of several local modes of two, three, or four atoms connected by bonds for stretching, bending, or torsional and out-of-plane local modes, respectively.

The basis of calculations are the following:

 1. Obligatory:

  • geometry of the structure (atom orientation) in cartesian coordinates,
  • force-field (F matrix) in cartesian coordinates.

2. Desirable:

  • calculated frequencies and atom displacement matrix (ADM)

VEDA 4 extracts automatically the necessary data from the Gaussian94/98/03 output files (.log and .fch)

The introductory file containing the set of internal coordinates (.dd2) is generated by VEDA, but the user can defined his own set as well.

 VEDA 4 enables three ways to analyze the distribution of vibrational energy:

  • Manual editing of the Base coordinates (with the help of Alternative coordinates),
  • Mixing Modes procedure (optional),
  • Optimization procedure.

 All this ways can be combined.

Veda additional informations:

  1. If .log and .fmu files are correct, the .fmv file is generated. The .fmv file is useful in the next start of the analysis. Then the .log and .fmu files are not necessary.
  2. When .dd2 file is edited, you can remove the modes assignments. Then Veda automatically generates the new ones.
  3. When you add a line (at the end of the file) in the .fmv (.fmu) file: scaling factor = a * x + b (a, b – numbers) then in the .vdf file the scalled freqencies are generated. To easy convert the results to the table in an editor, the | sign as the column separator is added.
  4. When Veda finds the .mpo file in the folder, Veda reads it, otherwise the .mpo file is generated.
  5. You can renumerate an atom : place in the .fmv (.fmu) file liner enumerating atoms, followed by two columns: old number, new number. If the number is the same, it can be omitted. Also, you can write two in the reversed order: new number, old number. You can put the renumerated atoms in the .dd2 file, but the renumeration is reversed.
  6. When editing the .dd2 file, the definitions can be introduced as follow: name of mode followed by 2 (3, 4) atom numbers, for example: 1 stre 12 15.
  7. You can introduce the user coordinates in the .dd2 file. Then the user modes can be omitted in the next optimization by choosing „hide user coordinates” in the control box. Similarly, you can hide the othercoordinates, e.g., stre, bend, tors, out, etc.
  8. Linear dependence of the coordinates: sometimes Veda creates a set of coordinates which is linearly dependent. Especially, this may happen for very symmetric structures. Veda offers some ways to deal with such a problem:

a) old version of the .dd2 creation (control box) – it uses another way of the coordinate definitions. This option also helps when the usual .dd2 creation generates too small set of coordinates.

b) test alternative until TED<999 (control box)

c) generate .dd2 without coordinates of the „out” type of the modes „in plane”

d) ring coordinates – for structures with ring

e) exchange groups of coordinates – alternative .dd2 button

f) manual edit of coordinates – it can be successful for structures with intermolecular bonds.

g) in hopeless cases send me the .fmv file.

Download

 VEDA4 program (Windows)

Examp_1 and Examp_2 contain files for exemplary molecules.

Some additional information can be find in  veda_use.doc

If Veda not act because of lack of the MSVBVM50.DLL, put MSVBVM50.DLL file into your VEDA folder

 VEDA4xx Veda version for up to 480 atoms.

VEDA