Table 3.3. Effect of stretching on the lowest-frequency normal twisting mode and elastic modulus of a 100 bp generic DNA homopolymer^*.

Coupled variables	r (Å)	(r - req)/req (%)	Y/Y0†	${\nu }_1^{\mathrm{str}}$ (cm-1)	C (10-19 erg-cm)
	344.0	5.2	0.89	0.187	2.09
Tilt-Roll	343.9	5.2	0.89	0.187	2.09
Tilt-Twist	344.0	5.2	0.89	0.188	2.12
Tilt-Shift	344.0	5.2	0.89	0.187	2.09
Tilt-Slide	344.0	5.2	0.89	0.187	2.09
Tilt-Rise	343.8	5.2	0.91	0.187	2.09
Roll-Twist	344.0	5.2	0.89	0.197	2.32
Roll-Shift	344.0	5.2	0.89	0.187	2.09
Roll-Slide	344.1	5.3	0.88	0.187	2.09
Roll-Rise	345.0	5.5	0.78	0.188	2.10
Twist-Shift	344.0	5.2	0.89	0.186	2.07
Twist-Slide	344.0	5.2	0.89	0.184	2.04
Twist-Rise	344.0	5.2	0.88	0.195	2.28
Shift-Slide	343.9	5.2	0.90	0.187	2.09
Shift-Rise	344.4	5.4	0.84	0.186	2.09
Slide-Rise	343.2	5.0	0.98	0.185	2.08
Roll-Twist,Twist-Rise	344.0	5.2	0.89	0.211	2.67
Twist-Slide,Twist-Rise	344.0	5.2	0.89	0.197	2.32
Roll-Twist,Twist-Slide	344.0	5.2	0.89	0.212	2.69
Roll-Twist,Twist-Slide,Twist-Rise	344.0	5.2	0.88	0.224	3.01

^*Dimeric rest state: $({\theta }_1^0,{\theta }_2^0,{\theta }_3^0,{\theta }_4^0,{\theta }_5^0,{\theta }_6^0)=(0°,2.8°,33.8°,0\mathrm{Å},-0.2\mathrm{Å},3.33\mathrm{Å})$.

^†Young’s modulus, Y, of the restrained duplex with designated conformational properties compared to that, Y₀, of the free, ideal DNA duplex without coupling.