I find a rotation matrix which best describes how to get from one set of atomic coordinates (molecular geometry) to another by just a pure rotation.
The rotation matrix R is defined
R=V \left( \begin{array}{ccc}<br />
1 & & \\<br />
& 1 & \\<br />
& & \left|VU^T\right| \end{array} \right)U^T<br />
where V and U are from the SVD of matrix K:
K=V\Lambda U^T[\tex]<br />
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K is formed by summing over i the outer products of the coordinate vectors of atom i in the first and second geometry. (i follow the method described at http://homepages.inf.ed.ac.uk/rbf/CVonline/LOCAL_COPIES/MARBLE/high/pose/least.htm" )<br />
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I.e K depends on atomic coordinates, and so do U and V.<br />
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I require the derivative of each element of R with respect to atomic coordinate. (The rotation matrix is used in an energy approximation and I need analytic forces)<br />
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Any answers or hints much appreciated.
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#3
saulg
3
0
I think I've found the answer I needed in the following paper:
Are there known conditions under which a Markov Chain is also a Martingale? I know only that the only Random Walk that is a Martingale is the symmetric one, i.e., p= 1-p =1/2.
Hello !
I derived equations of stress tensor 2D transformation.
Some details: I have plane ABCD in two cases (see top on the pic) and I know tensor components for case 1 only. Only plane ABCD rotate in two cases (top of the picture) but not coordinate system. Coordinate system rotates only on the bottom of picture.
I want to obtain expression that connects tensor for case 1 and tensor for case 2.
My attempt:
Are these equations correct? Is there more easier expression for stress tensor...