CheckCIF-CELLV01

PROC-NAME: CELLV01 Type_1

PURPOSE: To check that the _cell_volume matches _cell_length_ and _cell_angle_ values.

PROCEDURE:

CALCULATE

S = {_cell_angle_alpha+_cell_angle_beta+_cell_angle_gamma}/2

VOL = _cell_length_a*_cell_length_b*_cell_length_c*2*SQRT{SIN[S]*SIN[S-_cell_angle_alpha]*SIN[S-_cell_angle_beta]*SIN[S-_cell_angle_gamma]}

RV = _cell_volume/VOL

TEST

IF RV is 0.999 <> 1.001 issue ALERT A

        "Alert A The supplied cell volume differs from that calculated from the cell parameters. Ratio outside the range 0.999 <> 1.001"

        There is a discrepancy between the unit cell volume given in the CIF and that calculated from the unit cell dimensions given in the CIF. Check the volume and cell dimensions for typographical errors.

(http://journals.iucr.org/services/cif/checking/CELLV_01.html)

目的：检查单胞体积(_cell_volume)与单胞长度(_cell_length_)和单胞角度(_cell_angle_)是否相符。

若RV小于0.999或大于1.001，发布A类警告

        "Alert A The supplied cell volume differs from that calculated from the cell parameters. Ratio outside the range 0.999 <> 1.001"

        CIF中由单胞尺寸计算出的单胞体积与给定值不相符。检查是否单胞体积与单胞尺寸排版错误。

解决策略：一般不会出现这种情况，检查是否晶胞参数输入错误。