PROC-NAME: DIFMX02 Type_1

PURPOSE: To check that if _refine_diff_density_max is not within expected limits that the adjacent site is identified.

PROCEDURE:

DMAX = _refine_diff_density_max

DTEST = 0.1 * ZMAX

TEST

IF DMAX > DTEST*.75 atom site should be identified.

Issue ALERT C

? ? ? ? ?"Alert C The minimum difference density is > 0.1*ZMAX*0.75 The relevant atom site should be identified."

? ? ? ? The maximum residual electron density is larger than normally expected. Please specify the name of the nearest atom to this maximum and its distance from the maximum.

(http://journals.iucr.org/services/cif/checking/DIFMX_02.html)

目的：檢查_(kāi)refine_diff_density_max是否不在確定相鄰位置的預(yù)期范圍內(nèi)。

過(guò)程：

DMAX = _refine_diff_density_max

DTEST = 0.1 * ZMAX

檢查

若DMAX > DTEST*.75原子位置應(yīng)被識(shí)別

則發(fā)布C級(jí)警告

? ? ? ?? "Alert C The minimum difference density is > 0.1*ZMAX*0.75 The relevant atom site should be identified."

? ? ? ? 最小殘余電子密度值比預(yù)期更負(fù)。請(qǐng)指定最接近此最小殘余電子密度峰的原子名稱及它們之間的距離。

警告原因：最小殘余電子密度值超出預(yù)期范圍。

解決策略：C級(jí)警告一般可以不處理。若確定沒(méi)有其他問(wèn)題，則指定最接近此最小殘余電子密度峰的原子名稱及它們之間的距離。

關(guān)于該警告的一個(gè)具體解釋例子參考下面鏈接中的公眾號(hào)文章： https://mp.weixin.qq.com/s/irYbkyXuk1kRluJryBZYeg