On 16/11/2011 5:46 AM, Nilesh Dhumal wrote:
Hello,
I am trying to calculate the dihedral angle between four points.
I considered two planes (ABC& BCD) and calculate the dot products of two
normals (n1 and n2)to these plane.
theta=cos-1(n1.n2)
I compared theeta values of dihedral angle with ampac and some values are
negative. I am geting all positive value.
Any one knows how to calculate sign of dihedral angle.
The sign of the angle is determined by the order in which the atoms
define the plane. Conventionally, the normal of ABC is in the opposite
direction of the normal of CBA, and the two angles those normals form
with the normal of BCD have equal magnitude but opposite sign of their
cosine.
Mark
--
gmx-users mailing list gmx-users@gromacs.org
http://lists.gromacs.org/mailman/listinfo/gmx-users
Please search the archive at
http://www.gromacs.org/Support/Mailing_Lists/Search before posting!
Please don't post (un)subscribe requests to the list. Use the
www interface or send it to gmx-users-requ...@gromacs.org.
Can't post? Read http://www.gromacs.org/Support/Mailing_Lists
