Bond Stretch and Angle Bending Cross Term

Bond Stretch and Angle Bending Cross Term 

Like MM2, MM-t includes coupling between bond stretching and angle bending. If the angle is defined to include atoms i, j, and k, where k is the central atom, then MM-t couples stretching of the ik and jk bonds with the angle  

If atom i or atom j is a hydrogen, the deformation (r-r ) is considered to be zero. Thus, no stretch-bend interaction is defined for XH2 groups. The stretch-bend force constants are incorporated 

The constant 2.51118 converts between MM-t stretch-bend force constants expressed in millidynes per radian and HyperChem s default, kcal per degree. 

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