Table 2 Mean occupancy (q) of the corresponding σ* orbitals for each CO···HN, CO···HαCα front, CO···HαCα inner and CO···HαCα outer H-bond/interaction between PPII helices in the different interfaces at the M06-2X/6-31 + G(d) level of theory
From: Hydrogen bonding patterns and cooperativity in polyproline II helical bundles
q(σ*) (10−2 electrons) | Interface | Number of PPII Helices | |||
|---|---|---|---|---|---|
2 | 3 | 4 | 5 | ||
CO···HN | ab | 3.590 | 3.601 | 3.607 | 3.609 |
bc | - | 4.154 | 4.188 | 4.196 | |
cd | - | - | 4.226 | 4.255 | |
CO···HαCα Front | ab | 1.806 | 1.795 | 1.794 | 1.794 |
bc | - | 1.787 | 1.775 | 1.776 | |
cd | - | - | 1.805 | 1.794 | |
CO···HαCα Inner | ab | 1.944 | 1.961 | 1.960 | 1.958 |
bc | - | 2.016 | 2.034 | 2.032 | |
cd | - | - | 1.964 | 1.986 | |
CO···HαCα Outer | ab | 1.357 | 1.357 | 1.357 | 1.358 |
bc | - | 1.610 | 1.606 | 1.607 | |
cd | - | - | 1.642 | 1.639 | |
