To use all functions of this page, please activate cookies in your browser.
With an accout for my.chemeurope.com you can always see everything at a glance – and you can configure your own website and individual newsletter.
- My watch list
- My saved searches
- My saved topics
- My newsletter
Additional recommended knowledge
Z-matrices can be converted to cartesian coordinates and back, the information content is identical. They are used for creating input geometries for molecular systems in many molecular modelling and computational chemistry programs. A skillful choice of internal coordinates can make the interpretation of results straightforward. Also, since Z-matrices can contain molecular connectivity information (but do not always contain this information), quantum chemical calculations such as geometry optimization may be performed faster, because an educated guess is available for an initial Hessian matrix, and more natural internal coordinates are used rather than Cartesian coordinates.
The methane molecule can be described by the following cartesian coordinates (in Ångströms):
C 0.000000 0.000000 0.000000 H 0.000000 0.000000 1.089000 H 1.026719 0.000000 -0.363000 H -0.513360 -0.889165 -0.363000 H -0.513360 0.889165 -0.363000
The corresponding Z-matrix, which starts from the carbon atom, could look like this:
C H 1 1.089000 H 1 1.089000 2 109.4710 H 1 1.089000 2 109.4710 3 120.0000 H 1 1.089000 2 109.4710 3 240.0000
Categories: Molecular modelling | Computational chemistry
|This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Z-matrix_(chemistry)". A list of authors is available in Wikipedia.|