Identify the closer donor-H...acceptor direction in each supplied conformer, assign its local interaction force constant using the pair-specific lookup, and state which local interaction is stiffer and by what ratio. Does this establish which entire conformer is thermodynamically more stable?

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 S0007: N3 is covalently bonded to H4 and H5; hydroxyl O13 is covalently bonded to H14. Conformer B is S0008: N11 is covalently bonded to H12 and H13; hydroxyl O5 is covalently bonded to H4. For each conformer compare N-H...O and O-H...N directions using the shortest donor-H to opposite-heteroatom distance, with its donor-H-acceptor angle as a consistency check. Use this lookup ONLY for the supplied pair: N-H donor to hydroxyl-O acceptor has reported local interaction force constant 0.150 millidynes/angstrom; O-H donor to N acceptor has 0.201 millidynes/angstrom. Do not treat the lookup as a universal value for a bond type.

Attachment S0007:
14
Coordinates in angstrom; atoms numbered from 1.
C 1.4076 -0.2178 -0.0026
O 2.3605 -0.9897 0.0260
N 1.5654 1.1340 -0.0441
H 2.5019 1.4832 0.0480
H 0.7797 1.7510 0.0378
C 0.0240 -0.7420 -0.0146
H -0.0283 -1.8188 -0.0256
C -1.1416 -0.0757 -0.0004
C -2.4764 -0.7417 -0.0052
H -3.0446 -0.4620 0.8838
H -3.0503 -0.4363 -0.8819
H -2.3703 -1.8215 -0.0212
O -1.1769 1.2961 0.0203
H -2.0963 1.5786 0.0346


Attachment S0008:
14
Coordinates in angstrom; atoms numbered from 1.
C 1.1439 -0.0462 -0.0029
C 0.0228 -0.7783 0.1943
H 0.1266 -1.8386 0.3559
H 0.2435 1.5542 -0.4421
O 1.1690 1.2652 -0.3243
C 2.5174 -0.6156 0.0806
H 3.1008 -0.0582 0.8123
H 3.0162 -0.5119 -0.8820
H 2.4905 -1.6631 0.3629
O -2.2874 -0.9775 -0.3051
N -1.5009 1.1067 0.2421
H -2.4756 1.3703 0.1846
H -1.0735 1.4338 1.0988
C -1.3467 -0.2825 0.0363