CheckCIF-PLAT601-608
PLAT601 Type_2 Test for (Unreported) solvent accessible voids
Crystal structures in general do not contain large solvent accessible voids in the lattice. Most structures lose their long-range ordering when solvent molecules leave the crystal. Only when the remaining network is strongly bonded (e.g. zeolites and some hydrogen bonded networks) the crystal structure may survive.
Residual voids in a structure may indicate the omission of (disordered) density from the model. Disordered density may go undetected when smeared since peak search programs are not designed to locate maxima on density ridges. The presence or absence of residual density in the void may be verified on a printed/plotted difference Fourier map or with PLATON/SQUEEZE. Voids of 40 Ang**3 may accommodate H2O. Small molecules such as Tetrahydrofuran have typical volumes in the 100 to 200 Ang**3 range. This test reports the volume of the largest solvent accessible void in the structure.
A paper reporting a crystal structure with a significant solvent accessible void should at the least discuss the issue.
(http://journals.iucr.org/services/cif/checking/PLAT601.html)
例:PLAT601_AlERT_2_B Structure Contains Solvent Accessible VOIDS of … 189.00? A**3
警告原因:晶體中存在孔洞。
解決策略:將孔洞存在的溶劑或者分子指認(rèn)出來,或者使用SQUEEZE扣除孔洞中的電子云密度。某些有孔洞的MOF可不予理會,否則需給出合理解釋。
PLAT602 Type_2 Test for TOO LARGE (Unreported) solvent accessible voids
This test reports on a solvent accessible void in the structure, too large or too time consuming for the current PLATON version for a more detailed analysis as part of the validation run. Use the SOLV option for more details. Such a warning might also indicate that the symmetry is incomplete e.g. should have been specified as P-1 and not P1, leaving out half of the unit cell content.
(http://journals.iucr.org/services/cif/checking/PLAT602.html)
例:PLAT602_ALERT_2_A VERY LARGE Solvent Accessible VOID(S) in Structure !
警告原因:晶體中存在孔洞。
解決策略:將孔洞存在的溶劑或者分子指認(rèn)出來,或者使用SQUEEZE扣除孔洞中的電子云密度。某些有孔洞的MOF可不予理會,否則需給出合理解釋。
PLAT603 Type_4 Test for TOO LARGE Unit Cell for VOID search
No search for solvent accessible VOIDS done as part of VALIDATION in view of large unit-cell.
(http://journals.iucr.org/services/cif/checking/PLAT603.html)
例:PLAT606_ALERT_4_G VERY LARGE Solvent Accessible VOID(S) in Structure ! Info
警告原因:晶體中存在孔洞。
解決策略:將孔洞存在的溶劑或者分子指認(rèn)出來,或者使用SQUEEZE扣除孔洞中的電子云密度。某些有孔洞的MOF可不予理會,否則需給出合理解釋。
PLAT604 Type_4 Test for TOO Many VOIDS
Too many solvent accessible VOIDS.
(http://journals.iucr.org/services/cif/checking/PLAT604.html)
警告原因:晶體中存在孔洞。
解決策略:將孔洞存在的溶劑或者分子指認(rèn)出來,或者使用SQUEEZE扣除孔洞中的電子云密度。某些有孔洞的MOF可不予理會,否則需給出合理解釋。
PLAT605 Type_4 Test for (Reported) solvent accessible voids
Crystal structures in general do not contain large solvent accessible voids in the lattice. Most structures lose their long-range ordering when solvent molecules leave the crystal. Only when the remaining network is strongly bonded (e.g. zeolites and some hydrogen bonded networks) the crystal structure may survive.
Residual voids in a structure may indicate the omission of (disordered) density from the model. Disordered density may go undetected when smeared since peak search programs are not designed to locate maxima on density ridges. The presence or absence of residual density in the void may be verified on a printed/plotted difference Fourier map or with PLATON/SQUEEZE. Voids of 40 Ang**3 may accommodate H2O. Small molecules such as Tetrahydrofuran have typical volumes in the 100 to 200 Ang**3 range. This test reports the volume of the largest solvent accessible void in the structure.
A paper reporting a crystal structure with a significant solvent accessible void should at the least discuss the issue.
Note: The use of PLATON/SQUEEZE was reported in the CIF.
(http://journals.iucr.org/services/cif/checking/PLAT605.html)
警告原因:晶體中存在孔洞。
解決策略:將孔洞存在的溶劑或者分子指認(rèn)出來,或者使用SQUEEZE扣除孔洞中的電子云密度。某些有孔洞的MOF可不予理會,否則需給出合理解釋。
PLAT606 Type_4 Test for TOO LARGE (Reported) solvent accessible voids
This test reports on a solvent accessible void in the structure, too large or too time consuming for the current PLATON version for a more detailed analysis as part of the validation run. Use the SOLV option for more details. Such a warning might also indicate that the symmetry is incomplete e.g. should have been specified as P-1 and not P1, leaving out half of the unit cell content.
(http://journals.iucr.org/services/cif/checking/PLAT606.html)
警告原因:晶體中存在孔洞。
解決策略:將孔洞存在的溶劑或者分子指認(rèn)出來,或者使用SQUEEZE扣除孔洞中的電子云密度。某些有孔洞的MOF可不予理會,否則需給出合理解釋。
PLAT607 Type_4 Test for Skipped VOID Test
Void test Skipped
(http://journals.iucr.org/services/cif/checking/PLAT607.html)
警告原因:晶體中存在孔洞。
解決策略:將孔洞存在的溶劑或者分子指認(rèn)出來,或者使用SQUEEZE扣除孔洞中的電子云密度。某些有孔洞的MOF可不予理會,否則需給出合理解釋。
PLAT608 Type_4 Test for too many atoms for ADDSYM test as part of CheckCIF
The ADDSYM test is skipped as part of the checkCIF run when the symmetry generated cell content gets too large and the calculation too time consiming. The calculation can still be done via the ADDSYM tool in PLATON.
(http://journals.iucr.org/services/cif/checking/PLAT608.html)
警告原因:結(jié)構(gòu)中原子過多,因此在線check CIF跳過ADDSYM檢查。
解決策略:可用PLATON中的ADDSYM進(jìn)行此項(xiàng)檢查。