CheckCIF-PLAT790-799

PLAT790 Type_4 Test Whether C.G. Residue in Unitcell Box

Unless for a good reason, molecular species should be transformed (by symmetry and/or translation) so that their centres of gravity are close to or within the unit-cell bounds. This is a strict rule for the main species. Deviations from this general rule are for smaller additional species when relevant for intermolecular interactions with the main species.

(http://journals.iucr.org/services/cif/checking/PLAT790.html)

例：PLAT790_ALERT_4_C Centre of Gravity not Within Unit Cell: Resd. # 1 C47 H31 Ir N2 O4

警告原因：C47 H31 Ir N2 O4分子重心不在单胞内。

解决策略：要平移或对称操作后，使得大部分原子的分数坐标都在单胞内，即大部分原子的坐标都是正分数，而不是1.xxx或-0.xxxx。具体可在.ins中加move指令或在xp中用sgen

在ins中添加命令“MOVE 1 0 0 -1”，然后精修；或者直接把该分子的坐标加1减1，使之主体在单胞内，就可以了。

或者在xp中，

arad 0.2 2 atom name

envi atom name

sgen

file

等指令操作后，也可以。

若使用OLEX2，则可以使用“Centre on Cell”(下图所示)按钮使分子重心落在单胞内。

若使用shelXle，则可以使用“move centers of gravity into unit cell” (下图所示)按钮使分子重心落在单胞内。

PLAT791 Type_4 Check the absolute configuration of chiral atom in 'chiral' spgr

This test addresses the consistency of the absolute configuration assignment in non-centrosymmetric structures with proper symmetry operations (i.e. all matrices with determinant = 1) only. Verify the (R/S) absolute configuration assignment of this atom and the consistency of the absolute configuration implicit in the CIF-data with that in the 'ORTEP' illustration. Torsion angles should have the correct sign. The absolute structure assignment should also be consistent with the lowest value of the Flack parameter and/or know absolute configuration.

(http://journals.iucr.org/services/cif/checking/PLAT791.html)

例1：PLAT791_ALERT_4_G The Model has Chirality at C7 (Chiral SPGR) S Verify

例2：PLAT791_ALERT_4_G The Model has Chirality at C8 (Chiral SPGR) R Verify

警告原因：结构中C7为S构型(例1)/C8为R构型(例2)，请确认。

解决策略：一般无需处理，确认是否正确即可。

PLAT792 Type_1 Check the absolute configuration of chiral atom in 'non-chiral' spgr

This test addresses the consistency of the absolute structure assignment (i.e. polarity etc.) in non-centrosymmetric structures in space groups that include improper symmetry operations (e.g. mirror planes). Check the (R/S) absolute configuration assignment of this atom and the consistency of the absolute configuration implicit in the CIF-data with that in the 'ORTEP' illustration.

(http://journals.iucr.org/services/cif/checking/PLAT792.html)

例1：PLAT792_ALERT_1_G Note: The Model has Chirality at C1 (Verify) S

例2：PLAT792_ALERT_1_G Note: The Model has Chirality at C2 (Verify) R

警告原因：结构中C1为S构型(例1)/C2为R构型(例2)，请确认。

解决策略：一般无需处理，确认是否正确即可。

PLAT793 Type_4 Check the absolute configuration of chiral atom in centrosymmetric spgr

This test addresses the consistency of the absolute configuration assignment of molecules in the reported asymmetric unit among coordinates, molecular presentations and chemical diagrams. Check the (R/S) absolute configuration assignment of this atom and the consistency of the absolute configuration implicit in the CIF-data with that in the 'ORTEP' illustration.

(http://journals.iucr.org/services/cif/checking/PLAT793.html)

例：PLAT793_ALERT_4_G The Model has Chirality at C14 (Verify) .... R

警告原因：结构中C14为R构型，请确认。

解决策略：一般无需处理，确认是否正确即可。

PLAT794 Type_5 Report the calculated 'Valence Bond' valency for metals

This test reports the valency of an atom as predicted by the Valence

Bond Model. See:

N.E. Brese & M. O'Keeffe (1991) Acta Cryst. B47, 192-197.

I.D. Brown (2002). The Chemical Bond in Inorganic Chemistry: The Bond Valence Model. Oxford University Press.

More explicit info on the calculations can be obtained by running the calculations explicitly with the PLATON option BondValence.

Note: The underlying theory is empirical and might not apply to the case at hand (e.g. charged species).

(http://journals.iucr.org/services/cif/checking/PLAT794.html)

例1：PLAT794_ALERT_5_G Tentative Bond Valency for Cu1(II)

例2：PLAT794_ALERT_5_G Note: Tentative Bond Valency for Zn1 (II) 1.99

警告原因：Cu1(例1)/Zn1(例2)原子上成键数不常见。

解决策略：无需解决，有合理解释即可。

PLAT798 Type_4 Test for Alphanumeric Label on coordinate record

Atom labels are generally not a number (i.e. starting with one or two characters indicating the atom type). Labels can be erroneously numeric due to typing errors (e.g. 'Oxygen' typed as 'zero').

(http://journals.iucr.org/services/cif/checking/PLAT798.html)

警告原因：原子标签为数字。

解决策略：一般是误操作，重新精修生成CIF即可。

PLAT799 Type_4 Test for Alphanumeric Label on displacement par. record

Atom labels are generally not a number (i.e. starting with one or two characters indicating the atom type). Labels can be erroneously numeric due to typing errors (e.g. 'Oxygen' typed as 'zero').

(http://journals.iucr.org/services/cif/checking/PLAT799.html)

警告原因：原子标签为数字。

解决策略：一般是误操作，重新精修生成CIF即可。