PLAT081 Type_1 - NoMaximum Shift/Error Given

A maximum shift/error should be specified in order to judge convergence.

(http://journals.iucr.org/services/cif/checking/PLAT081.html)

警告原因：未在CIF中給出偏移值。

解決策略：一般為誤刪除，重新精修生成CIF即可。

PLAT082 Type_2 Test for reasonable R1

A higher than usual R1 indicates either an insufficient model or poor quality data.

(http://journals.iucr.org/services/cif/checking/PLAT082.html)

警告原因：R1值較大。

解決策略：檢查是否已經(jīng)精修權(quán)重，再檢查模型是否正確，最后檢查數(shù)據(jù)質(zhì)量是否足夠高。

PLAT083 Type_2 Test for extreme second weighting parameter (SHELXL)

The second parameter on the SHELXL weighting line has an exceptionally large value. This may indicate either improper reflection s.u.s or an unresolved problem such as missed twinning.

(http://journals.iucr.org/services/cif/checking/PLAT083.html)

警告原因：權(quán)重因子中第二個(gè)數(shù)值較大，可能由于某些點(diǎn)擬合誤差較大或者孿晶。

解決策略：OMIT掉誤差較大的點(diǎn)或者按孿晶精修。

PLAT084 Type_3 Test for reasonable wR2

wR2 will in general have a value twice of that of R1 with refinement on F**2. Significantly larger values usually indicate a poor refinement model. Also check for unaccounted for twinning.

(http://journals.iucr.org/services/cif/checking/PLAT084.html)

警告原因：wR2值較大，一般來說wR2值約是R1值的兩倍。

解決策略：檢查是否已經(jīng)精修權(quán)重，再檢查模型是否正確，最后檢查數(shù)據(jù)質(zhì)量是否足夠高或是否孿晶。

PLAT085 Type_2 Test for default SHELXL weighting scheme

The weighting scheme is found to be left at the SHELXL default. This default is recommended for the preliminary structure refinement. It is uncommon that this unoptimized weight gives the best final refinement result.

(http://journals.iucr.org/services/cif/checking/PLAT085.html)

警告原因：在最后結(jié)果中，權(quán)重的系數(shù)為SHELXL給出的默認(rèn)值，未進(jìn)行精修。

解決策略：精修權(quán)重即可。

PLAT086 Type_2 Test for reasonable S (Too Low)

S should in general be close to 1 at the end of a refinement with a proper weighting scheme. If not, there might be significant unresolved problems with the model.

(http://journals.iucr.org/services/cif/checking/PLAT086.html)

警告原因：權(quán)重值為遠(yuǎn)小于1。

解決策略：檢查是否已經(jīng)精修權(quán)重，再檢查模型是否正確，最后檢查數(shù)據(jù)質(zhì)量是否足夠高或是否孿晶。

PLAT087 Type_2 Test for reasonable S (Too High)

S should in general be close to 1 at the end of a refinement with a proper weighting scheme. If not, there might be significant unresolved problems with the model.

(http://journals.iucr.org/services/cif/checking/PLAT087.html)

警告原因：權(quán)重值為遠(yuǎn)大于1。S值較大

解決策略：檢查是否已經(jīng)精修權(quán)重，再檢查模型是否正確，最后檢查數(shù)據(jù)質(zhì)量是否足夠高。

PLAT088 Type_3 Test for reasonable Data / parameter ratio (centro)

The data/parameter ratio should in general be higher than 10 for a quality structure determination. This ratio can be improved by not refining C-H parameters other than riding on their carrier atom.

(http://journals.iucr.org/services/cif/checking/PLAT088.html)

警告原因：對(duì)于中心對(duì)稱結(jié)構(gòu)，數(shù)據(jù)參數(shù)比最好大于10。

解決策略：可以采用騎式模型減少參數(shù)個(gè)數(shù)，無法解決只能重新還原或者收集數(shù)據(jù)。

PLAT089 Type_3 Test for reasonable Data / parameter ratio (non-centro) (Zmax < 18)

The data/parameter ratio should in general be higher than 7 for a quality determination of a structure containing atoms with Z less than 18. This ratio can be improved by not refining C-H parameters other than riding on their carrier atom.

Note: The number of reflections used in this ratio is the number obtained by Laue group averaging.

(http://journals.iucr.org/services/cif/checking/PLAT089.html)

警告原因：對(duì)于非中心對(duì)稱結(jié)構(gòu)，且晶胞內(nèi)分子數(shù)小于18，數(shù)據(jù)參數(shù)比最好大于7。

解決策略：可以采用騎式模型減少參數(shù)個(gè)數(shù)，無法解決只能重新還原或者收集數(shù)據(jù)。

PLAT090 Type_3 Test for reasonable Data / parameter ratio (non-centro) (ZMAX > 18)

The data/parameter ratio should in general be higher than 8 for a quality determination for a structure containing heavy atoms with ZMAX greater than 17. This ratio can be improved by not refining C-H parameters other than riding on their carrier atom.

(http://journals.iucr.org/services/cif/checking/PLAT090.html)

警告原因：對(duì)于非中心對(duì)稱結(jié)構(gòu)，且晶胞內(nèi)分子數(shù)小于18，數(shù)據(jù)參數(shù)比最好大于8。

解決策略：可以采用騎式模型減少參數(shù)個(gè)數(shù)，無法解決只能重新還原或者收集數(shù)據(jù)。刪除omit或者shel命令重新精修。

例：Alert level B

??????????? Crystal system given = trigonal

PLAT090_ALERT_3_B Poor Data / Parameter Ratio (Zmax > 18) ........?????? 5.15 Note

解決策略：數(shù)據(jù)收的不夠?qū)е铝藦?qiáng)點(diǎn)參數(shù)比低于最低要求7，所以才會(huì)出現(xiàn)這個(gè)錯(cuò)誤，要解決的話只能重新收數(shù)據(jù)了，再收的時(shí)候不要按照空間群收了，要收四分之一球或二分之一球。