Which conformer satisfies both the stated short-contact and directional criteria for the indicated O-H...O arrangement? Report H...O distance and O-H...O angle for A and B, then classify each. Explain why donor-acceptor proximity alone is not sufficient.

Use the complete supplied XYZ coordinates in angstrom without optimization. Atom row numbers are one-based after the two XYZ header lines. Atom correspondence is given separately for each conformer; do not assume row numbers match across files. These are computed conformers, not solution measurements. Conformer A is asset S0005: hydroxyl donor O6, its covalently bound H5, and carbonyl acceptor O14. Conformer B is asset S0006: hydroxyl donor O5, its covalently bound H14, and carbonyl acceptor O6. The numbers locate atom rows, not file line numbers. For this geometry-screening exercise require H...O <= 2.2 angstrom and O-H...O angle >= 130 degrees (vertex at H). These are explicit task criteria, not a universal definition of hydrogen bonding.

Attachment S0005:
14
Coordinates in angstrom; atoms numbered from 1.
C 1.1679 -0.0705 0.0003
C -0.0054 -0.7575 -0.0073
C -1.2628 -0.0311 -0.0040
H 0.0109 -1.8351 -0.0197
H 0.2587 1.5453 0.0028
O 1.2197 1.2584 0.0073
C 2.5078 -0.7195 0.0012
H 3.0645 -0.4049 0.8827
H 3.0700 -0.3954 -0.8734
H 2.4225 -1.8019 -0.0050
N -2.4053 -0.7683 -0.0315
H -2.3779 -1.7539 0.1480
H -3.2714 -0.2776 0.1026
O -1.3180 1.2134 -0.0022


Attachment S0006:
14
Coordinates in angstrom; atoms numbered from 1.
C -1.3359 0.0434 -0.0285
H -0.0391 -1.7351 -0.1183
C 1.1689 -0.0649 0.0023
C -0.0391 -0.6578 -0.0510
O 1.2971 1.2792 0.0882
O -1.4834 1.2539 -0.0865
N -2.4169 -0.8174 0.0136
H -3.2967 -0.3752 0.2206
H -2.2852 -1.7402 0.3865
C 2.4479 -0.8375 -0.0261
H 3.0513 -0.5323 -0.8826
H 2.2643 -1.9049 -0.0955
H 3.0267 -0.6418 0.8782
H 2.2367 1.4872 0.1216