2-amino purine BOND CQ-CB 469. 1.404 ANGLE NC-CA-NC 70. 129.1 CQ-CB-CB 85. 117.3 CB-CQ-H5 35. 120.0 CB-CQ-NC 70. 117.3 CQ-CB-NB 70. 132.4 DIHEDRAL X -CQ-CB-X 4 10.2 180. 2.