From: Axel Kohlmeyer (
Date: Sat Jan 02 2010 - 03:33:38 CST

> But as much as I know, the normal D-H-A angle is always an obtuse, because
> for the ideal H bond,
> D, H and A are line in a straight line, that is, the angle of D-H-A should
> be 180 degr.
> Furthermore, I tested an snapshot. If I use the criterion 20 degr.
> A H-bond with D-H-A angle of 153.74 is shown(Viewed with
> Mouse-->Label-->Angle).
> Could any one tell me why the criterion is an acute angle?

hydrogen bond angles are not measured like this.
you have to measure the A-D-H angle and there an
ideal h-bond has an angle of 0.

please have a look at the literature about hydrogen bonds.


> 2010-01-02
> ________________________________
> yongle
> Ph. D. student
> Institute of Theoretical and Computational Chemistry
> School of Chemistry and Chemical Engineering
> Nanjing University
> 22 Hankou Road, Nanjing, Jiangsu 210093
> P. R. China

Dr. Axel Kohlmeyer
Institute for Computational Molecular Science
College of Science and Technology
Temple University, Philadelphia PA, USA.