CheckCIF-PLAT370-380

PLAT370 Type_2 Test for short C3 - C2 (Angstrom Difference) XRAY: 1.31

Large deviations from generally accepted values may indicate model problems, over refinement etc. Default C3-C2 = 1.31 Ang. (X-Ray) value from Ladd & Palmer, Structure Determination by Xray Crystallography (1985).

Note:

- C3-C2 indicates a bond between an atom with 3 bonds and one with 2 bonds.

- Conjugated systems may cause some 'false alarm' messages.

(http://journals.iucr.org/services/cif/checking/PLAT370.html)

警告原因：C(sp2)-C(sp)键键长过短。

解决策略：检查是否需要无序处理，或用DFIX限制距离后精修。

PLAT371 Type_2 Test for long C3 - C2 (Angstrom Difference) XRAY: 1.31

Large deviations from generally accepted values may indicate model problems, over refinement etc. Default C3-C2 = 1.31 Ang. (X-Ray) value from Ladd & Palmer, Structure Determination by Xray Crystallography (1985).

Note:

- C3-C2 indicates a bond between an atom with 3 bonds and one with 2 bonds.

- Conjugated systems may cause some 'false alarm' messages.

(http://journals.iucr.org/services/cif/checking/PLAT371.html)

警告原因：C(sp2)-C(sp)键键长过长。

解决策略：检查是否需要无序处理，或用DFIX限制距离后精修。

PLAT372 Type_2 Test for short C2 - C2 (Angstrom Difference) XRAY: 1.25

Large deviations from generally accepted values may indicate model problems, over refinement etc. Default C2-C2 = 1.25 Ang. (X-Ray) value from Ladd & Palmer, Structure Determination by Xray Crystallography (1985).

Note:

- C2-C2 indicates a bond between atoms with 2 bonds each.

- Conjugated systems may cause some 'false alarm' messages.

(http://journals.iucr.org/services/cif/checking/PLAT372.html)

警告原因：C(sp)-C(sp)键键长过短。

解决策略：检查是否需要无序处理，或用DFIX限制距离后精修。

PLAT373 Type_2 Test for long C2 - C2 (Angstrom Difference) XRAY: 1.25

Large deviations from generally accepted values may indicate model problems, over refinement etc. Default C2-C2 = 1.25 Ang. (X-Ray) value from Ladd & Palmer, Structure Determination by Xray Crystallography (1985).

Note:

- C2-C2 indicates a bond between atoms with 2 bonds each.

- Conjugated systems may cause some 'false alarm' messages.

(http://journals.iucr.org/services/cif/checking/PLAT373.html)

警告原因：C(sp)-C(sp)键键长过长。

解决策略：检查是否需要无序处理，或用DFIX限制距离后精修。

PLAT374 Type_2 Test for long N - N Bond (> 1.45 Angstrom)

Large deviations from generally observed bond distances may indicate model problems, over-refinement etc. Check for wrong atom-type assignments. For an example see: Acta Cryst. (2003) E59, m710-m712.

(http://journals.iucr.org/services/cif/checking/PLAT374.html)

警告原因：N-N键键长过长。

解决策略：键长是否原子指认错误，检查是否需要无序处理，或用DFIX限制距离后精修。

PLAT375 Type_2 Test for C-O-H with large C-O Distance

Strange C-O-H geometry with C-O > 1.45 Angstrom detected. Wrong Atom Type ?

(http://journals.iucr.org/services/cif/checking/PLAT375.html)

警告原因：C-O键键长过长。

解决策略：键长是否原子指认错误，检查是否需要无序处理，或用DFIX限制距离后精修。

PLAT380 Type_4 Test for incorrectly Oriented Methyl Moiety

This test alerts for possible incorrectly oriented CH3 moieties. (E.g. AFIX 33 instead of AFIX 137 etc. within the SHELXL realm)

(http://journals.iucr.org/services/cif/checking/PLAT380.html)

例：PLAT380_ALERT_4_G Check Incorrectly? Oriented X(sp2)-Methyl Moiety

警告原因：末端甲基AFIX处理方式有错。

解决策略：一般需改成用AFIX 147处理，除非有合理解释。