CheckCIF-PLAT430-434

PLAT430 Type_2 Test for short non-bonding inter D...A contacts

This test alerts for possibly missed Hydrogen bonds as indicated by short (i.e. shorter than sum of the van der Waals radii - 0.2 Angstrom) Donor - Acceptor distances.

Note: Short C=O .. O=C are observed sometimes when part of three-centre O-H, N-H or C-H O..O bridging.

(http://journals.iucr.org/services/cif/checking/PLAT430.html)

例：PLAT430_ALERT_2_B Short Inter D…A Contact O2…N1…2.66 Ang.

警告原因：按照给出距离，O2和N1之间距离较近，可能存在氢键。

解决策略：给O2和N1重新加氢，使之间形成氢键，否则需要给出合理解释。

Author Response: O2 is the oxygen atom of lattice water molecules. N1 is the nitrogen atom from one terminal CN. There are strong hydrogen bonds between them, and the distance between them is reasonable for donor and acceptor atoms with strong hydrogen bonding.

PLAT431 Type_2 Test for short non-bonding inter HL...A contacts

This test reports on short intermolecular Halogen .. Donor/Acceptor atom-type distances.

此检查报告短分子间卤素…供体/受体原子类型距离。

(http://journals.iucr.org/services/cif/checking/PLAT431.html)

警告原因：按照给出距离，卤素与供体/受体之间存在氢键。

解决策略：仔细检查是否原子指认错误，给卤素外另一个原子加氢使之形成氢键。否则需要给出合理解释。

PLAT432 Type_2 Test for short non-bonding inter X...Y contacts

This test raised an ALERT for short intermolecular contacts. In general, intermolecular contact distances should be not much smaller than the sum of the associated van der Waals Radii. More often than not, such short contacts can be a warning sign for errors. All short contacts should therefore be examined in some detail. Interesting exceptions are carbonyl-carbonyl interactions that often feature short O...C contacts (see Allen et al. (1998) B54, 320-329, short NO2 O...O interactions and BF4(-) to (aromatic) carbon contacts.

(http://journals.iucr.org/services/cif/checking/PLAT432.html)

例：PLAT432_ALERT_2_G Short Inter X...Y Contact O68 .. C2 2.97 Ang

警告原因：按照给出距离，O68和C2之间距离较近，可能存在氢键。

解决策略：O68和C2重新加氢，使之间形成氢键，否则需要给出合理解释。

PLAT433 Type_4 Test for short non-bonding minor..minor inter X...Y contacts

This test raised an ALERT for short intermolecular contacts between minor disorder components. In general, intermolecular contact distances should be not much smaller than the sum of the associated van der Waals Radii. More often than not, such short contacts can be a warning sign for errors. All short contacts should therefore examined in some detail. Interesting exceptions are carbonyl-carbonyl interactions that often feature short O...C contacts (see Allen et al. (1998) B54, 320-329).

(http://journals.iucr.org/services/cif/checking/PLAT433.html)

警告原因：按照给出距离，X和Y之间距离较近，可能存在氢键。

解决策略：X和Y重新加氢，使之间形成氢键，否则需要给出合理解释。

PLAT434 Type_2 Test for short non-bonding inter HL...HL contacts

This test reports on short intermolecular Halogen .. Halogen type distances.

此检查报告短分子间卤素…卤素类型距离。

(http://journals.iucr.org/services/cif/checking/PLAT434.html)

警告原因：分子间卤素距离较近。

解决策略：仔细检查是否原子类型指认错误，否则需要给出合理解释。